 CONTENTS: 
 
   Preface 
 
   Chapter 1.   Introduction 
      Table 1.1    Character CONVENTIONS 
 
   Chapter 2.   The MPSIM Environment 
 
   Chapter 3.   Tutorial 
 
   Chapter 4.   Functional Categories of MPSIM Commands 
      Table 4.1    MPSIM Commands by Function (Quick Referenc) 
  
  Chapter 5.   MPSIM Commands - Detailed Descriptions 
      Table 5.1    MPSIM Commands - Brief Alphabetical Listing  
 
    Troubleshooting Guide 
    Customer Support 
    PIC16C5X User's Guide Addendum 
    PIC16C64 User's Guide Addendum 
    PIC16C65 User's Guide Addendum 
    PIC16C71 User's Guide Addendum 
    PIC16C73 User's Guide Addendum 
    PIC16C74 User's Guide Addendum 
    PIC16C84 User's Guide Addendum 
    PIC17C42 User's Guide Addendum 
    PIC17C43 User's Guide Addendum 
    PIC17C44 User's Guide Addendum 
 
 
Preface 
MPSIM is a discrete-event simulator tool designed to: 
   -  Imitate operation of Microchip Technology's PIC16C5X, PIC16CXX and  
              PIC17CXX families of microcontrollers 
   -  Assist users in debugging software that uses Microchip  
              microcontroller devices 
 
A discrete-event simulator, as opposed to an in-circuit emulator, is designed  
to aid in the debugging of the general logic of your software. The MPSIM  
discrete-event simulator allows users to modify object code and immediately  
re-execute, inject external stimuli to the simulated processor, and trace the  
execution of the object code. A simulator differs from an in-circuit emulator  
in three important areas: I/O timing, execution speed, and cost. 
  
I/O Timing 
External timing in MPSIM is processed only once during each instruction cycle.  
Transient signals, such as a spike on MCLR smaller than an instruction cycle  
will not be simulated but may be caught by an in-circuit emulator. In MPSIM,  
external stimulus is injected just before the next instruction cycle  
execution. 
 
Execution Speed 
The execution speed of a discrete-event simulator is several orders of  
magnitude less than a hardware-oriented solution. Users may view slower  
execution speed as a handicap or a blessing. Some discrete-event simulators  
are unacceptably slow. MPSIM however, attempts to provide the fastest possible  
simulation cycle. 
 
Cost 
The cost of the debugging tool may be an issue with some developers. For this  
reason, Microchip Technology has developed this simulator to be a cost- 
effective tool for debugging application software. MPSIM does not require any  
external hardware to the PC, which keeps the cost at a minimum. 
The simulator, however, is a great debugging tool. It is particularly suitable  
for optimizing algorithms. Unlike the emulator, the simulator makes many  
internal registers visible and can provide more complex break points. 
If you are a new user, refer to Chapter 3 for a Getting Started tutorial.  
Device specific information is provided in the appendices at the end of the  
manual.  
 
 
 
Chapter 1.   Introduction 
 
Introduction 
MPSIM is a discrete-event simulator designed to aid you in debugging your  
software applications for Microchip Technology's PIC16C5X, PIC16CXX, and  
PIC17CXX microcontrollers.  
 
Highlights 
Whether you are an experienced user or a beginner, we strongly suggest that  
you read this chapter first since it provides information about: 
   -  Installing MPSIM  
   -  Documentation conventions 
   -  Device-specific support 
   -  Customer support information. 
 
If this is your first time using MPSIM we also suggest that you go through the  
tutorial provided in Chapter  3. This tutorial introduces all files that are  
used or generated by the simulator and provides a good introduction to some of  
the most widely-used commands.  
Installing MPSIM 
 
System Requirements 
MPSIM requires an IBM PC or compatible running DOS version 3.0 or later. The  
PC needs a 3 1/2 inch floppy disk drive and at least 640K main memory. We  
recommend a hard disk with at least 5 MB of available space.  
   -  On the PC, create a new directory for the MPSIM software and  
       change to that directory: 
      MKDIR SIM<RETURN> 
      CD SIM<RETURN> 
 
   -  Copy all the files on the MPSIM diskette into the above directory: 
      COPY a:\*.*  
 
After loading the software, MPSIM is ready to run. 
 
Document Conventions  
This section describes the conventions this manual uses for the data you are  
to enter. 
 
Table 1.1- Character CONVENTIONS 
Character                        Represents 
Square ([]) brackets             Optional arguments 
Angle (<>) brackets              Delimiters for special keys: <TAB>, <ESC>,  
                                    etc. 
Pipe (|) characters              Choice of mutually exclusive arguments; an OR  
                                    selection 
Lower case characters            Type of data 
 
Terminology 
 
Breakpoints 
Source code locations where you want the code to cease execution. 
 
Program Counter (PC) 
The address in the loaded program at which execution will begin or resume. 
 
Disassembler  
Converts modified object code back into assembly-language code when a listing  
file wasn't loaded. Thus, mnemonic information can display even when you have  
made changes. 
 
Step 
A single executable instruction. You can single-step through a program by  
executing one instruction at a time with the SS command. A stimulus file can  
inject values onto specified pins at specified steps. 
 
Symbols 
Alphanumeric identifiers such as labels, constant names, bit location names  
and file register names. MPSIM understands both explicit data/addresses and  
symbols. 
 
Trace 
A trace file can be created to illustrate the execution flow of your program.  
Each line in the trace file contains the object code, source line, step  
number, elapsed time, and file registers that have changed. Trace can be  
limited to a range of addresses, or to a specific file register address.  
Please see Chapter 3 Tutorial for examples on the trace file. When you trace  
the instructions, they always display on the screen. If you previously opened  
a trace file and have not closed it, MPSIM also appends the trace to the file. 
 
View screen 
The portion of your monitor that dynamically displays the values in specified  
data areas. It is seven lines long. The V command creates a view screen; the  
AD command adds data areas to the display; the DV command deletes data area  
from the display; and the NV command deletes all data areas from the view  
screen. 
 
Device-Specific Support 
MPSIM v. 5.x provides support for more than one family of microcontrollers.  
Chapters 1 - 5 contain general information about MPSIM, regardless of the  
target processor. Device-specific information can be found in the appendices  
at the end of this manual.  
 
Customer Support 
If you have any questions about MPSIM, the first step is to check in  
Appendix A, which contains a troubleshooting guide that provides some common  
error messages and their possible causes. Appendix C provides detailed  
information about how to connect to the Microchip Technology BBS. The BBS  
contains the most up-to-date development systems software, application notes,  
as well as a variety of other useful information. If you still cannot find the  
answer, contact the sales office nearest you. Information and telephone  
numbers are presented on the last page of the manual. 
 
 
 
Chapter 2.   The MPSIM Environment 
 
Introduction 
Chapter 2 provides an introduction to the MPSIM debugging environment. It  
describes all data areas that can be simulated and presents general  
information about using the simulator. This chapter is highly recommended for  
first-time users. 
Highlights 
The following topics will be covered: 
   -  Layout of the User Interface 
   -  I/O Pins 
   -  CPU model including reset, sleep, WDT, registers and stack 
   -  Files Used and Generated by MPSIM 
   -  Hex-Code Formats 
   -  Invoking MPSIM 
 
User Interface 
The user interface consists of three areas: the title line, the view screen  
and a command entry/display region. The title line remains in a fixed location  
at the top of the screen and lists the current hex file, the radix, the MPSIM  
version, the controller being simulated, cycle steps and elapsed time. 
 
Figure 2.1  Start-up 
The view screen displays user selected pin and register values. This area is  
created by the user typically through an initialization command file. This  
file will be in greater detail later in this chapter in Files Used and  
Generated by MPSIM. 
 
The command entry/display region occupies the remainder of the screen. Use  
this area to enter commands; MPSIM enters any responses to a command on the  
line or lines immediately following the command. 
 
MPSIM can be invoked with any or a combination of the following options: 
 
Option               Description           Default 
  -v                  verbose                off 
  -m               monochrome mode           off 
  -c           MPASM assembler support       MPASM 
  -a                 ASCII only                off 
 
Invoking MPSIM 
The '%' is MPSIM's prompt. Enter a hex code filename. MPSIM will  
assume .HEX for MPASM. To load a file into the simulator, use the following  
command: 
     %LO filename [FORMAT] <RETURN> 
 
I/O Pins 
There is a list of viewable and modifiable pins for each microcontroller in  
its appendix. These pin names are loaded when a processor is selected and are  
the only ones that MPSIM recognizes as valid. 
 
I/O Pin Modeling 
Because a conflict can occur when a pin is being driven internally (via an  
instruction) and externally (via stimulus file), the following table is  
provided to illustrate the possible conditions and the order in which MPSIM  
processes it. 
 
 Is the pin being              Is the pin being           Resolution 
 driven externally?            driven internally? 
 
     Yes                              Yes               Chip wins. 
     No                                No        The pins are essentially  
                                                  floating. The pins maintain  
                                                  the last external value they  
                                                  were driven. 
     Yes                               No         Simple. 
 
*Note that this does not represent the actual behavior of the circuit  
when the I/O pin was last driven by the chip. However, typically, a used I/O  
pin (especially CMOS) would not be left floating. 
 
Pin Signals 
At the end of each instruction all pins are checked for possible input or  
output. 
   -  If the MCLR pin is cleared, MPSIM simulates a MCLR reset. 
   -  The TRIS (or DDR for the PIC17CXX) status bits determine how MPSIM  
manipulates the port and file register bits. For example, the TRISA, RA0-RA5  
and F5 registers work together; the TRISB, RB0-RB7 and F6 registers work  
together; and the TRISC, RC0-RC7 and F7 registers work together, etc. 
  - For TRIS status register bits that are set, MPSIM reads the  
     corresponding port bit into the corresponding file register bit. 
  - For TRIS status register bits that are cleared, MPSIM writes the  
     corresponding file register bit to the corresponding port bit (pin). 
   -  Similarly, if any of the timer inputs are changed, the corresponding  
       timer or its prescaler will increment. 
   -  Any peripheral input (such as capture input) is acted upon. 
   -  Any peripheral output (such as serial port output) is presented on  
       the pin. 
 
CPU Model 
 
Reset Conditions 
All reset conditions are supported by MPSIM.  
 
A Power-On-Reset, for example, can be simulated by using the RS instruction.  
All special-purpose registers will be initialized to the values specified in  
the Microchip data sheet. 
 
A MCLR reset during normal operation or during SLEEP, for example, can easily  
be simulated by driving the MCLR pin low (and then high) either via the  
stimulus file or by using the SE command.  
 
A WDT time-out reset is simulated when WDT is enabled (see DW command) and  
proper prescaler is set (by initializing OPTION register appropriately for the  
PIC16CXX family or by using the FW command for the PIC17CXX family) and WDT  
actually overflows. WDT time-out period is approximately the normal time for  
the device being simulated (to closest instruction cycle multiple).  
 
The Time-out (TO) and Power-down (PD) bits in the Status register reflect the  
reset condition. This feature is useful for simulating various power-up and  
time out forks in the user code. 
 
Sleep 
MPSIM simulates the SLEEP instruction, and will appear asleep until a wake-up  
from sleep condition occurs. For example, if the Watchdog timer has been  
enabled, it will wake the processor up from sleep when it times out (depending  
upon the prescaler setting).  
 
Another example of a wake-up-from-sleep condition, would be Timer1 wake-up  
from sleep. In this case, when the processor is asleep, Timer1 would continue  
to increment until it overflows, and if the interrupt is enabled, will wake  
the processor on overflow and branch to the interrupt vector. 
 
Wake-up from SLEEP through interrupt is fully simulated in the PIC16CXX and  
PIC17CXX products. 
 
WDT 
The Watchdog timer is fully simulated in the MPSIM simulator. Because it is  
fuse-selectable on the device, it must be enabled by a separate command (see  
the DW command) in MPSIM. The period of the WDT is determined by the prescaler  
settings. The basic period (with prescaler = 1) is approximated at 18 ms (for  
the PIC16C5X and PIC16CXX families and 12 ms for the PIC17CXX families). 
 
Registers 
MPSIM simulates all registers. Certain special-function registers or non- 
mapped registers can be added to the viewscreen or modified like any other  
register. Examples are timer prescaler or postscalers. 
 
All registers are initialized appropriately at various reset conditions. 
Please see the appendix of the microcontroller in question for a list of  
additional registers. 
 
Register Name         Function 
     W                Working Register 
     TRISA            Tris register for Port A (PIC16C5X/PIC16CXX) 
     TRISB            Tris register for Port B (PIC16C5X/PIC16CXX) 
     TRISX (etc)*      (etc)* 
     DDRB             Data Direction Register for PIC17CXX 
     OPT              Option register* 
* Processor-dependent. For a complete list for a given processor, please  
refer to the device-specific appendix. 
 
Hardware Stack 
 
Push 
The CALL instruction pushes the PC value + 1 to the top of the stack and loads  
the PC with the address of the subroutine being called. If the number of CALL  
instructions exceeds the depth of the stack, MPSIM will issue a STACK OVERFLOW  
warning message when executing or single-stepping through code. In the  
PIC16C5X family, the CALL instruction is the only instruction that causes an  
address to be pushed to the stack. The PIC16CXX and PIC17CXX families,  
however, support interrupts. When an interrupt occurs, the PC value + 1 is  
pushed to the stack and the PC is loaded with the address of the interrupt  
vector. The same error message will also be generated if too many addresses  
are pushed to the stack when MPSIM is executing or single-stepping through a  
program. 
 
Pop  
RETLW instructions in the PIC16C5X and RETLW, RETURN and RETFIE instructions  
in the PIC16CXX and PIC17CXX instruction set remove or pop the last address  
pushed to the stack and loads its value into the PC. If an attempt is made to  
pop more values than the stack contains, MPSIM will issue a STACK UNDERFLOW  
warning message when executing or single-stepping through the program.  
Because stack implementation is processor-family dependent, please refer to  
the appendix of the processor family in question for stack simulation. 
 
Files Used and Generated By MPSIM 
MPSIM uses or creates the following I/O files. 
   -  Command files 
   -  Initialization files 
   -  Journal files 
   -  Stimulus files 
   -  Assembler files 
   -  HEX-Code formats 
The following sections describe each of these files. 
 
Command Files 
Command files are text files containing MPSIM commands. These MPSIM commands  
are executed with the GE command. 
 
There are two special command files: MPSIM.INI and MPSIM.JRN. MPSIM.INI is the  
initialization file that MPSIM will automatically load on start-up. MPSIM.JRN  
is a file containing all commands executed in the previous session. 
 
Initialization File 
When MPSIM is invoked, it automatically performs the MPSIM commands in  
MPSIM.INI. Common commands in this file might create a standard view screen  
and/or initialize data areas. Figure 3.2 in Chapter 3 lists an example  
initialization file and Figure 3.3 in Chapter 3 shows the resulting view  
screen. 
 
Journal File 
If you want to re-execute the most recent MPSIM session, LJ retrieves a list  
of the commands performed during the previous MPSIM session from MPSIM.JRN.  
This file is automatically created each time MPSIM is invoked. If you want to  
retain a journal file, copy it to another filename before reentering MPSIM.  
The first time you reenter MPSIM, the journal file is the same as you copied.  
However, when you exit via Q, the commands from the current MPSIM session will  
overwrite the previous journal file. Thereafter, you can access the copied  
file with GE. 
 
As with all modern CAD/CAE tools, the concept of journal files is carried  
throughout MPSIM. That is, any command entered by the user is automatically  
stored in a journal file (named MPSIM.JRN). The journal file remains in the  
user's default directory regardless of the termination method (Quit or Abort).  
The LJ command loads and executes the journal file created during the previous  
simulator session. However, it doesn't store the commands from the previous  
journal file in the current journal file. 
 
Performing the Q command removes the previous journal file, but using the AB  
(Abort) retains old journal file. The current MPSIM session commands are  
written over the previous journal file. 
 
Stimulus File 
This file allows you to schedule bit manipulation by forcing MPSIM to drive  
given pins to given values at a specified input step. This scheduling is via a  
text file called a stimulus file. The stimulus file can force any pin to any  
value at any input step during program execution. The ST command reads the  
stimulus file into MPSIM. When you execute the loaded file with E, each time  
it looks for input, it reads the next step in the stimulus file. The first  
line of stimulus file always consists of column headings. It lists first the  
word STEP, followed by the pins that are to be manipulated. The data below  
STEP represents the object file's input request occurrence. The data below  
each pin name is the input value. You may enter comments at the end of a line  
by preceding it with an exclamation mark (!).   The following example  
illustrates the stimulus file format: 
 
STEP   pin 1  pin 2      ! These are pin names 
  8      1      0        ! followed by values 
 16      0      1 
 24      1      0 
 
Other notes on the format of stimulus file: 
   -  The steps in the stimulus file must be decimal, regardless of the  
       radix in which you run your simulation 
   -  The number of spaces separating data tokens is irrelevant 
   -  Backslash (\) is a continuation mark at the end of a line and indicates  
       that the following line continues the statement from the current line 
 
Step    RTCC    RA3    RA2    RA1     RA0       ! Column Headings 
 3       0       0      1      0       0        ! Stimulus before cycle 3 
 4       1       0      1      0       1        ! Injected before cycle 10 
 9       1       1      0      1       0        ! Injected before cycle 16 
10       0       1      0      1       1        ! Stimulus before cycle 3 
15       0       0      0      0       0        ! Injected before cycle 9 
16       1       0      0      0       1        ! Injected before cycle 15 
Figure 2.2  - Stimulus File 
 
There are three other ways to inject stimulus to the I/O pins in addition to  
using the stimulus file. A clock can be assigned to an I/O pin, Alt-function  
keys can be assigned to the pins (only for use in execute mode), and they can  
be modified in single step mode. Details and syntax for each command can be  
found in Chapter 5. Please see CK, DK, and SE commands. 
 
Files Generated by the Assembler 
The MPASM assembler generates by default all files necessary, for use with  
MPSIM. To assemble a file, invoke MPASM with the source file name as follows: 
     MPASM filename 
 
The default assembler that MPSIM assumes is MPASM. To specify MPALC as the  
assembler, invoke MPSIM with the -s option. 
 
Listing File 
The listing file contains the source code the assembler uses to create the  
object code being simulated. To display the source code throughout simulation,  
read in the listing file with the LO command. Otherwise, MPSIM uses the  
disassembler. 
 
Input Hex File 
The input hex file contains the object code generated by the assembler. The 
LO command reads an hex file directly into program memory. The hex code 
format can be INHX8M or INHX8S. The default format is INHX8M. 
 
Output Hex File 
At any time during simulation, the contents of the program memory can written  
to an external file with the O command. The hex code format can be INHX8S or  
INHX8M. 
 
Symbol File 
The assembler generates the symbol file and contains a collection of symbols  
used in the source code. This file is used for symbolic debugging, and is  
automatically loaded when the LO command is used. The RA command clears the  
symbol file, and restores all original values.  
 
Trace File 
If you open a trace file with the TF command and later trace execution, MPSIM  
writes the specified trace into the trace file as well as displaying the trace  
on-line. 
 
HEX Code Formats 
The simulator is capable of reading or generating two different hex code  
formats as dictated by the LO and O commands: INHX8S or INHX8M. The default  
hex code format that the simulator recognizes is INHX8M, but any file format  
can be loaded by specifying the format when using the LO command. For example: 
      LO Myfile INHX8S 
will tell the simulator to load myfile.obh and myfile.obl. (The two files  
necessary for INHX8S format.) Similarly, modified hex code can be saved to  
disk in any format by using the following command: 
      O Myfile INHX8M 
 
The file that has been loaded into memory in any format will now be saved as a  
file in INHX8M format.  
 
 
 
Chapter 3.   Tutorial 
 
Introduction 
This chapter provides an introduction to MPSIM, the discrete-event simulator  
for Microchip Technology's PIC16C5X, PIC16CXX and PIC17CXX families of  
microcontrollers.   It also presents a step-by-step tutorial through a sample  
program, SAMPLE.ASM.  The tutorial is intended to familiarize you with the  
simulator and to provide an introduction to some of the most commonly used  
commands.    The source code for SAMPLE.ASM and the other files used in the  
tutorial are available on your master disk, and can also be found in Appendix  
B at the end of the manual.  If you do not have soft copies of the files for  
the tutorial, they can be created with any ASCII text editor.  It is assumed  
that MPASM and MPSIM have been installed on your hard drive, and that all  
files used in the tutorial are in your working directory. 
 
The program that is used in this tutorial, SAMPLE.ASM, is a software  
multiplier that takes two 8-bit numbers, mulplr and mulcnd, and places the 16- 
bit result in H_byte and L_byte.  
 
Because this chapter provides some background examples in addition to the  
tutorial, all steps that are part of the tutorial will have a step number  in  
bold text to the left of the command in the margin. 
 
Assemble the Code 
Before you can begin to use the simulator, you must first assemble SAMPLE.ASM.   
MPASM generates a hex file in INHX8M format by default.  In addition to  
INHX8M, the following formats can be output: 
      INHX8M 
      INHX8S 
There is one default setting that the simulator assumes when it loads your  
code: the file format.  The default file format for MPSIM is INHX8M, but any  
format that either assembler generates can be loaded into the simulator.   
For this tutorial, we want the output file format to be INHX8M (the default  
format used by MPSIM), and the processor type to be PIC16C54.  Type the  
following at the DOS prompt: 
     MPASM sample /p16C54 <RETURN> 
 
Invoke the Simulator 
To invoke the simulator, simply type  
     MPSIM<RETURN> (if using the MPASM assembler) 
       or 
     MPSIM -s<RETURN> (if using the MPALC assembler) 
at the DOS prompt.   
 
 
MPSIM.INI 
Observe the information in the command area and the information that is  
displayed in the view screen.  The data areas appear in the view screen  
because an initialization file, MPSIM.INI is in your working directory.   
MPSIM.INI is simply an ASCII file that contains  the same commands that appear  
in the command area.  Every time MPSIM is invoked, it looks for a file called  
MPSIM.INI.  If one exists on your working directory, all of the MPSIM commands  
appearing in that file will be executed, much like a DOS batch file.  It is  
important to understand that an initialization file can be named anything.   
MPSIM.INI is unique in that it is automatically loaded when MPSIM is invoked.   
 
Load the Initialization File 
Initialization files are very useful because they allow you to choose data  
areas that you wish to view, display them on the viewscreen, load your  
program, and create break points  - all in one step.  In other words, you can  
invoke MPSIM, load your initialization file, begin debugging, exit MPSIM, and  
return later, easily setting up the viewscreen the same way that you had it  
when you quit the program, simply by loading the initialization file. 
 
Creating an initialization file 
One easy way to create an initialization file is to first invoke the  
simulator, type in commands that set up your viewscreen, set some break  
points, and then quit the simulator.  When you quit, you will notice that a  
file MPSIM.JRN has been created.  This journal file contains every command  
that you executed in the previous session.  If  the W register, or any other  
register was added to the viewscreen, the commands implementing this will be  
saved in the journal file.  This file can then be edited using any text editor  
to remove commands such as E (execute) or Q (Quit), and then saved under  
another file name.  It is necessary to remove commands such as E and Q because  
they will also be executed when you load your ANYTHING.INI file, and the  
simulator would set up your viewscreen, execute your code, and quit.  It is  
also important to save the journal file under another name before invoking  
MPSIM a second time. Each time MPSIM is invoked, it overwrites the previous  
journal file, and if you did not rename the journal file, it will contain all  
commands executed in the current session.   
 
For this example, we will use the initialization file called SAMPLE.INI.  We  
will load it by using the following command: 
      GE  sample.ini <RETURN> 
MPSIM executes the commands in the following SAMPLE.INI file. 
LO SAMPLE 
ST SAMPLE 
SR X 
ZP 
ZR 
ZT 
RE 
P 54 
NV 
AD mulcnd 
AD mulplr 
AD H_byte 
AD L_byte 
AD count 
AD portb 
AD RB7,B,1 
AD RB6,B,1 
AD RB5,B,1 
AD RB4,B,1 
AD RB3,B,1 
AD RB2,B,1 
AD RB1,B,1 
AD RB0,B,1 
 
 
This changes the viewscreen so that it displays the data areas that SAMPLE.HEX  
uses, in the most useful format. 
 
The commands in this file create the viewscreen shown above and re-initialize  
data areas.  The viewscreen now contains data areas that can be watched during  
the execution of  SAMPLE.  
 
Load the Hex File  
Notice that the LO command is listed in the SAMPLE.INI file.  Because of this,  
the hex file was automatically loaded when SAMPLE.INI was loaded.  If the LO  
command were not in the SAMPLE.INI file, you could load the file by typing in  
the following: 
     LO sample <RETURN> 
It is important to realize that because we have assembled the code in the  
MPSIM default format (INHX8M), we do not have to specify the format being  
loaded.  If we had assembled filename in any format other than INHX8M, we  
would have had to load the file in the following way: 
     LO filename format <RETURN>  
MPSIM loads the named hex file, and then looks for a source file.  If the file  
is available, it also loads the symbol table and the listing file. 
 
Load the Stimulus File 
SAMPLE.INI has taken care of loading the stimulus file.  You can see in the  
SAMPLE.INI file that the command: 
     ST sample.sti <RETURN> 
was executed when the initialization file was loaded.   
 
The stimulus file contains values that are to be input to the pins.  When you  
execute the loaded program, at every instruction step specified in the  
stimulus file, MPSIM retrieves the input data, and injects their values to the  
pins.  
 
! Stimulus file for SAMPLE.ASM 
 
STEP      RB7   RB6   RB5   RB4   RB3   RB2   RB1   RB0   ! PortB Pins 
5          0     0     0     0     1     0     0     1    !  9 x 5 
7          0     0     0     0     0     1     0     1 
84         0     0     0     0     1     0     1     0    ! 10 x 5 
86         0     0     0     0     0     1     0     1 
163        0     0     0     1     1     0     1     1    ! 27 x 3 
165        0     0     0     0     0     0     1     1 
242        0     0     0     1     0     0     0     1    ! 17 x 7 
244        0     0     0     0     0     1     1     1 
321        0     1     0     0     0     0     0     0    ! 64 x 63 
323        0     0     1     1     1     1     1     1 
Figure 3.4- SAMPLE.STI Stimulus File 
 
The stimulus file for SAMPLE in figure 3.4 writes the multiplier and  
multiplicand values into simulated I/O port B.  Since this port allows up to  
eight bits of data, the maximum value of the multiplier and multiplicand is  
11111111 or 0xFF.   
 
Set Up Trace Parameters 
A trace file is a file that contains executed instructions, timing  
information, and registers that have been modified.  Using a trace file can be  
very helpful in determining where to inject stimulus and for creating a hard  
copy of the general execution flow of your program.  There are five MPSIM  
commands dealing with traces: 
   -  TF opens and closes a file for writing the traced data.   
   -  TA traces all instructions between two specified addresses 
   -  TC traces a specified number of instructions. 
   -  TR traces instructions dealing with specified registers and  
          values.   
   -  DX displays the current trace parameters 
 
Try some of the following exercises.  All of the traces in these exercises  
will be printed to a file.  If you would like to try printing your trace to a  
default printer, substitute PRN in place of the trace file name. 
 
Exercise 1: 
Trace the instructions between two labels, call_m and main, and print the  
instructions to a file.  
 
The first step is to create the trace file: 
     TF trace1.trc <RETURN> 
Next, specify the range of the trace. Then,  begin tracing the instructions.  
 
Hit any key to interrupt the trace. 
     TA main, call_m <RETURN> 
     TC <RETURN> 
 
Exercise 2: 
Trace fourteen instructions (0x0E instructions) and write the trace to the  
file TRACE2.trc. 
 
Restart the system by exiting MPSIM (q <RETURN>), and repeating steps 2  
(Invoke the Simulator) and 3 (Load the Initialization File). Just as in  
Exercise 1, we will first open the trace file 
      TF trace2.trc <RETURN> 
Then, we will trace the next fourteen instructions.  Note that if  the number  
of instructions to be traced is not specified, the trace will continue until a  
key is pressed.   
      TC E <RETURN>  
Note: If you had specified  the number of instructions to be executed as  
14 instead of  E, twenty steps would have been executed since the radix is set  
to hexadecimal (the default radix in MPSIM). 
 
Exercise 3: 
Check the current trace criteria. 
      DX <RETURN> 
The current trace parameters display in the command entry area of the MPSIM  
screen. 
 
Set Up Breakpoints 
Break points are used to artificially stop program execution so that you can  
review how the data has been manipulated or to see the contents of the Special  
Function Registers.  There are three instructions that deal with breakpoints: 
   -  DB displays all of the breakpoints currently set. 
   -  BC clears one or all of the breakpoints currently set. 
   -  B sets a break point. 
 
Exercise 1: 
Initialize the breakpoints by clearing any break points currently set.  Enter  
the following command: 
      BC 
 
Exercise 2: 
Set a breakpoint at MPY_S.  Enter the following command: 
      B mpy_S<RETURN> 
 
Exercise 3: 
Review all the breakpoints.  Enter the following command: 
      DB<RETURN> 
 
Exercise 4: 
Delete the breakpoint at MPY_S.  Enter the following command: 
      BC mpy_S<RETURN> 
 
Execute the Hex Code 
In addition to trace, there are three instructions that you can use  to  
execute your code.  
 
   -  E executes your code until it encounters a breakpoint or you press  
              a key. 
   -  SS single-steps through your instructions.  That is, it executes  
              one single instruction at the CPC. 
   -  C  Execute, ignoring n number of breakpoints. 
 
Exercise 1: 
Add a watch variable. Add the w register to the display. 
      AD W <RETURN> 
 
Exercise 2: 
Add two breakpoints and execute until the first breakpoint is encountered. 
      b main 
      b mpy_S 
      E <RETURN> 
 
MPSIM executes until it encounters the first breakpoint or until a key is  
pressed.  Watch the values change in the W, mulplr, H-Byte, and L-Byte  
registers.   
 
Exercise 3: 
Execute instructions one step at a time. 
      SS <RETURN> 
The SS instruction causes MPSIM to execute the instruction at the PC.     
Pressing <RETURN> at the MPSIM prompt re-executes the last command.  Execute a  
second instruction by pressing <RETURN> again. Do this several times, watching  
how the values in the W, mulplr, H-Byte, registers change.  This  command can  
be used to single-step through your entire program to see the data values at  
each step, and to watch the flow of your program.   If you supply an address  
with the SS command, MPSIM will modify the CPC to the address you specify and  
then will execute the instruction at that address.  Remember that pressing  
<RETURN> will cause MPSIM to re-execute the same command, so that if  you  
supplied an address with the command, the same address will be executed. 
 
Exercise 4: 
Execute your program and break after the second breakpoint. 
      C 2 <RETURN> 
 
MPSIM executes the instruction at the current CPC until the instruction  
immediately following the second break point.  Watch the values change in the  
W, mulplr, H-Byte, and L-Byte registers.  
 
Modify the Hex Code 
MPSIM has four types of  commands which allow you to modify the hex code:   
search commands locate code that match specified criteria, display/modify  
commands automatically display specified code and allow you to change it,  
delete commands eliminate specified code, output commands allow the modified  
code to be saved to a file. For the following exercises, mulplr is stored in  
file register F10.   
 
Exercise 1: 
Search for the next occurrence of F10, and change its contents to 0xFF. 
      SF 0, 1FF, F10 <RETURN> 
 
You will see two code lines with the "mulplr" register label. 
      F F10 <RETURN> 
After you type in the above command, you will see the current contents of  
register F10, followed by a colon.  Type in the value 0xFF, and watch the  
contents of the file register change.  You will see that the contents of  
mulplr will change since the value of mulplr is 0x10. 
 
Exercise 2: 
Change the value of the W register to 0x0C 
      W <RETURN> 
 
Just as in Exercise 1, you will see the current contents of W displayed on the  
screen, followed by a colon.  Type in 0x0C, and watch the contents of the W  
register change. 
 
Exercise 3: 
Change the contents of program memory located at the PC to a NOP. 
 
Type in the following: 
      M 0 <RETURN> 
You will see the contents of program memory displayed in hexadecimal, followed  
by a colon.  Type in a 0 (object code for NOP), and then  <RETURN>.  Unlike  
modifying file registers, you will not immediately exit the function.   
Instead, you will see the contents of the next memory location followed by a  
colon.  You can continue modifying program memory until you are finished.   
When you are done, type  Q.  This will get you back to the MPSIM command  
prompt (%). 
 
Exercise 4: 
Delete program memory between address 2 and 4. 
 
Type in the following command: 
      DE 2,4 <RETURN> 
This function will delete all program memory between 2 and 4 , and  will shift  
up remaining program memory.  If you would like to only clear the program  
memory between two addresses, use the following command: 
      ZM 2,4 <RETURN> 
 
Program memory between addresses 2 and 4 will now  
contain zeros (NOP instructions).  It will essentially leave a hole in program  
memory. Use the following command to view your changes: 
      DI 0 <RETURN> 
 
Exercise 5: 
Remove the modifications made to program memory from the object code in  
      ZP <RETURN> 
This instruction clears the patch table.  All of the modifications made to  
SAMPLE.HEX program memory are removed. 
 
Exit the MPSIM Session 
There are two ways of exiting MPSIM: 
      AB <RETURN> 
      Q <RETURN>  
 
Using the AB command causes the old journal file to remain the same.  The Q  
command overwrites the old journal file. 
 
You have now been introduced to some of the most commonly-used functions in  
the simulator, and should  have an understanding of how to use them.  If you  
need any additional information about any of the files that the simulator uses  
or generates, please review the information in Chapter 2.  Chapter 5 provides  
a list of all the commands that are available in MPSIM, complete with a  
detailed description of their functions and syntax.   
 
 
 
 
Chapter 4.   Functional Categories of MPSIM Commands 
 
Introduction 
Chapter 4 is intended to be used as a quick way to help locate a MPSIM command  
by function.  All of the commands presented in this chapter have been  
grouped together according to function instead of alphabetical order.  Once  
the desired command is found, it can be looked up in Chapter Five "MPSIM  
Simulator Commands" if a more detailed explanation or example is required.   
 
Highlights 
All commands have been divided into the following categories: 
 - Loading and Saving 
 - Inspecting and Modifying 
        Program Memory 
        File Registers and Pins 
        Timers 
        Display Functions 
        Patch Table 
        Symbol Table 
 - Executing and Tracing 
 - Modifying the View Screen 
 - Miscellaneous Commands  
 
 
Loading and Saving 
The following three commands load and save hex code and listing files. 
 
LO filename format 
Load file filename with format into program memory.  MPSIM also loads the  
source file. 
 
LS filename  
Load filename into internal symbol table. 
 
O filename format 
Write modified hex code to filename. 
 
Before simulation can begin, use LO to load an hex file into program memory. 
Immediately after loading the object file, MPSIM tries to load the listing  
file using the same filename and the extension .LST.  If MPSIM still can't  
find the listing file, the source code file cannot be loaded and displayed  
at breakpoints. Instead, MPSIM disassembles the hex code and displays the  
disassembled instruction. 
 
The object file can be any of two different formats: INHX85 or INHX8M. 
Example: 
      LO SAMPLE.OBJ INHX8M<RETURN> 
After modifications have been made to the program memory, the user may wish  
the save the corrected hex code into an external file.  Use the O command to  
output the hex code.   
 
Enter the filename including the extension. 
Example: 
O SAMPLE1.HEX INHX8S<RETURN>  
 
Inspecting And Modifying 
MPSIM allows user to change the values of any data area or program memory any  
time during the simulation. 
 
 
Program Memory 
In the course of testing a program, you may need to modify its instructions.   
Both the following commands do so. 
 
A address 
Display/modify program memory at address using symbolic format. 
 
M address 
Display/modify program memory at address using the current radix format. 
If you use IA, the source code for the address displays, followed by ':' on  
the next line for the new command.  The new command must consist of a valid  
mnemonic followed by zero or more operands. Each operand must contain a single  
value or symbol, no expressions will be allowed.  MPSIM interprets all values  
based on the current input radix as set with the SR command. 
 
Entering 'Q' at the prompt ends the command; entering '-' causes MPSIM to go  
back and inspect/modify the previous address; entering <RETURN> leaves the  
instruction alone and continues to the next address. 
 
After changing the hex code, the original source code no longer displays.   
It is replaced by a disassembled source line. 
 
If you use M, the contents of the address display in the same format as the  
current radix.   
 
The prompt ':' immediately follows the data.  Place the new value after the  
prompt, using the current radix. 
 
The '-', 'Q' and <RETURN> have the same affect as described above.  Two  
additional commands that affect program memory are: 
 
IN address,instruction 
Insert instruction at address in symbolic format. 
 
DE address1,address2 
Delete program memory from address1 to address2. 
The IN command places a symbolically formatted opcode at the given address,  
then displaces values that follow address by one location.  The new command  
must consist of a valid mnemonic followed by zero or more operands.  Each  
operand must contain a single value or symbol, no expressions will be allowed. 
 
The DE command deletes the code within the given boundaries then shifts all  
data in program memory locations greater than the upper boundary down to the  
lower boundary. 
 
 
Registers 
Each register can be inspected/modified by using the following commands: 
 
F register 
Display/modify contents of file register 
 
W 
Display/modify contents of  W register 
 
SC 
Display/modify processor cycle time 
 
SE data_area 
Display/modify any data_area 
 
RE 
Reset elapsed time and step count 
Inspect and modify file registers with the F command.  The value of the  
register displays followed by the prompt :.  Enter the new value after  
this prompt. 
 
 
Display Functions 
The display functions are provided to print formatted lists of various  
program variables in the command/source area on the screen. 
 
DR 
Displays the contents of all registers including W, status and the stack. 
 
DM addr1,addr2 
Displays the code from address1 to address2.  The code displays only in the  
current radix, not in mnemonics.  address1 must be less than address2 and  
both must be in the valid range of program memory. 
 
DI addr1,addr2 
Displays the code from address1 to address2.  The code displays in both the  
current radix and mnemonics. address1 must be less then address2 and both must  
be in the valid range of program memory. 
 
You can terminate the DM and DI commands at any time by pressing any key. 
 
Patch Table 
During the course of simulation, several changes may have been made to the  
hex code in order to achieve the desired results.  The patch table keeps  
track of all changes made by maintaining the original value of the address  
along with the most recent change.  The patch table can then be displayed  
out in symbolic format to aid the user in making changes to the source code.   
The following three commands manipulate the patch-table. 
 
ZP 
Clears the patch table and resets it to no patches made.  All changes  
previously made to the hex code remain. 
 
DP 
Display all patches in symbolic format. Both the original hex code and new  
code display. 
 
RP 
Restores all patches to their original value and clears the patch table 
Clearing Memory and Registers 
Memory and registers can be cleared quickly by using the following commands. 
 
ZM addr1,addr2 
Zero the program memory from address1 to address2.  address1 must less than  
address2 and both must be valid program memory addresses. 
 
ZR 
Zero all of the file registers (F0 through F31). 
 
ZT 
Zero the elapsed time counter. 
Clear any of the other data areas with the SE command. 
 
 
Searching Memory 
It is sometimes desirable to search the program memory for specific  
instructions or operands.  The following three commands search program  
memory for various patterns and display(?) each line containing that pattern. 
 
   SI address1,address2,instruction 
Search program memory from address1 to address2 for any occurrence of  
instruction.  Instruction is in mnemonic format. 
 
   SM address1,address2,m 
Search program memory from address1 to address2 for any occurrence of  
the value m.  Specify the search criteria in the radix mode, not in  
mnemonics. 
 
   SF address1,address2,register 
Search program memory from address1 to address2 for any instruction that  
accesses file register.  Specify the search criteria in the radix mode,  
not in mnemonics. 
 
 
Symbol Table 
The following commands manipulate the symbol table: 
 
DS 
Display symbol table. 
 
DL symbol 
Delete symbol from symbol table. 
 
GS symbol,value,type 
Generate symbol with a value of type.  type may be file, bit(file), label  
or literal.  See the GS command description for the exact syntax. 
 
Restore 
The Restore All command, RA, has the combined effect of restoring the patch  
table, clearing the symbol table and removing all break points. 
 
Execute and Trace 
The simulator executes in three basic modes, execute until break, single  
step or trace.  In either of these modes you can stop execution at any time  
by pressing any key. 
 
Execution Instructions 
The E command begins execution at the specified address, or at the CPC if  
you don't specify an address.  The loaded program executes until reaching a  
break point or until you press any key.  If you wish to slow down execution,  
use the single step instruction, SS.  SS executes the single instruction at  
the specified address or at the CPC if you don't specify an address. 
 
 
Tracing Execution 
 
In the trace mode, all addresses meeting certain conditions display as they  
execute.  The conditions may include: 
 - A given instruction within address boundaries. 
 - Accessing a given register. 
 - A given register containing a value between two limits.   
     The following trace parameters maintain trace execution. 
 - Register number being traced. 
 - Range of register values. 
 - Range of addresses to trace. 
 
 
The following commands set up and execute the trace mode. 
 
TC #instructions 
Trace the next #instructions.  If you omit #instructions, execution continues  
until MPSIM encounters a break point or until you press any key. 
 
TA 
Sets the upper and lower address trace limits to the full range of program  
memory. 
 
TA addr1,addr2 
Sets the lower validation limit for address trace to address1 and the  
upper address validation limit to address2. 
 
TR 
Sets the address trace to trace any file register. 
 
TR reg 
Sets the address trace to trace the file register. 
 
TR reg,min_val,max_val 
Sets the address trace to trace the file register only if the value of the  
register is between min_value and max_value. 
 
DX 
Displays the current trace parameters.  When in trace mode, the location,  
opcode, mnemonic, elapsed time, cycle steps and any changed data areas will  
be displayed when the given conditions are met. 
Note: 
F2 and F3 won't display if changed, however, status bits do display. 
Stack contents always display in brackets with the top of the stack  
to the left. 
 
 
Breakpoints 
 
MPSIM allows the user to set up to 512 breakpoints on any valid address.   
It also allows conditional breakpoints on any of the data areas.  When one of  
these breakpoints is encountered, the current address is displayed in symbolic  
format and control is returned to the user.  The following commands control  
the breakpoints. 
 
B address 
Set breakpoint at address (symbolic address can be used). 
 
B data_area op val 
Break when data_area matches the condition given by the  
operator (=,>,<,>=,<=,!=) and value. 
 
BC address 
Cancel breakpoint at address. 
 
BC data_area 
Cancel breakpoint involving data_area. 
 
BC 
Cancel all breakpoints. 
 
C #breakpoints 
Continue execution ignoring #breakpoints breakpoint occurrences. 
 
DB 
Display all active breakpoints. 
Only one conditional breakpoint is allowed per data area. 
 
 
View Screen 
The following commands set up and manipulate the view screen. 
 
V data_area,radix,#digits 
This command sets up the view screen.  This means that the View command  
defines the variables (and respective formats) to constantly display on the  
screen.  Once the view screen is set, it remains active until either a  
NOVIEW command or a View sets up a new view screen.  The format of this  
command is relatively simple.  Register or signal s displays in radix mode r  
with n digits. r defaults to hexadecimal and n defaults to 1.  If n is omitted,  
the number of digits is 1.  The radix can be binary, octal, hexadecimal  
or decimal. 
 
NV 
This command clears the view screen.  The same effect can be achieved by  
redefining the view screen. 
 
AD data_area,radix,#digits 
This command adds items to the view screen.  If one desires to add more display  
items to the view screen, use the Add command.  While this commands format is  
identical to View, it doesnt destroy the current contents of the view screen,  
but simply displays additional items as well as the current ones. 
 
DV data_area 
This command simply removes display items from the view screen while leaving  
the display formatting intact. 
 
TY data_area,radix,#digits 
This command changes the formatting of the existing view screen. s is the  
signal name (if the designated signal isnt in the view screen, MPSIM gives  
a warning).  The radix can be x, o, d or b and n is the number of spaces to  
reserve for this variable at the display  
time. 
 
 
Miscellaneous Commands 
 
SR radix 
This command sets the input/output radix to Octal, hexadecimal or Decimal.   
The radix will be used on all inputs and outputs with the exception of file  
register numbers and step counts. 
 
P {54|55|71|...} 
Choose the appropriate PIC16CXX Microcontroller number n.  n can be any member  
of the PIC16CXX or PIC16C5X microcontroller family.  The default is 55. 
 
GE filename 
This command forces MPSIM to get its command stream from an external text file.   
When end of file is reached, the control is returned to the user interface.   
All the incoming commands are parsed by the same mechanism as the one  
supervising the on-line interface thus the syntax should follow the guidelines  
of this document.  If the specified file is not found, the user will be  
notified. 
 
Q 
This command terminates the dialogue.  It prints out one or two summary  
messages, removes the journal file and exits to the operating system. 
 
AB 
This command aborts the dialogue.  It prints out one or two summary messages  
and exits to the operating system.   
 
ST filename 
Stimulus command allows the user to introduce an event-based stimulus  
injection into the model.  That is, the user may want to inject certain  
values into certain pins or registers at some point during the simulation.   
The stimuli are defined in a text file whose format is described on pages  
12 and 13. 
 
H 
The Help command lists the syntax and a brief summary of each command  
available in MPSIM. There are several screens of information. Press SPACEBAR  
to exit, any other key to display the next screen. 
 
CK pin, high, low 
This command allos you to assign a clock to an   I/O pin. 
 
DK altfxkey, pin, event 
This command simulates an asynchronous event through a function keystroke, and  
is very useful for simulating external interrupts or resets. 
 
FI FileNameAddr, PMemAddr, n  
This command injects values into a file register when the PC = PMEMAddr.  
MPSIM Commands 
 
 
The following table contains summary information grouped by function about  
the MPSIM commands. This information is also found on the MPSIM Quick  
Reference Card. Chapter 5 contains additional information about the MPSIM  
commands.  
 
Table 4.1 MPSIM Commands by Function 
 
MPSIM Conventions 
 
[   ]    Brackets indicate optional items. 
{   }    Braces indicate group options. One or more options in the group is  
          required. 
 |       Vertical bar indicates alternative options. 
 
 
System Navigation 
 
AB 
Abort Session. Aborts the dialogue, prints a summary message and exits to the  
operating system. AB does not overwrite the journal file. 
 
H|Help|? 
Help. The Help Command lists the syntax and gives a brief summary of each  
command available in MPSIM. Press the SPACEBAR to exit Help. Press any other  
key to display the next help screen. 
 
Q 
Quit. Terminates the dialog. Prints one or two summary messages, overwrites  
the old journal file and exits to the opening system. 
 
 
Program Memory 
 
DE address1,address2 
Delete Program Memory from address1 to address2. 
 
DI [address1[,address2]] 
Display Program Memory in Symbolic Format. Displays program memory from  
address1 to address2. Displays in current radix and symbolic format. Omit  
address2 to display next 10 lines from address1. 
 
DM [address1,address2] 
Display Program Memory in Radix Designated Format. (See SR command to set  
the radix.) Displays program memory from address1 to address2. Data displays  
in current radix only. With no parameter, displays 10 lines continuing from  
last DM display. 
 
FM address1,address2,pattern 
Fill Memory. Fills program memory from address1 to address2 with specified  
HEX pattern. 
 
IA address 
Insert/Inspect Assembly Code (Symbolic Format). Displays or modifies program  
memory at address using symbolic format. 
 
IN address,instruction 
Insert instruction. Inserts instruction at address in symbolic format. 
 
LO filename[format] 
Load Object File. Loads the object file, filename, with format into program  
memory. MPSIM also loads the listing file and symbol file. 
Valid Formats:    INHX8M  (Default) 
                  INHX8S 
 
M address 
Display/Modify Program Memory at Address. The contents at the address display,  
and a colon (:) prompt follows. To change the value at address, enter a new  
value (in the current radix) after the prompt. 
  Q         End the command 
  -         Cause MPSIM to go back to the previous address 
  <Enter>   Continue to the next address 
 
O filename [format] 
Output Modified Object Code. Writes contents of program memory, including  
modifications, to the specified file in the designated format. 
 
Valid Formats:     INHX8M  (Default) 
                   INHX8S 
                   INHX32 (for PIC17CXX) 
 
SF address1,address2,register 
Search Program Memory for Register. Searches program memory from address1 to  
address2 for any instruction that accesses the specified file register. 
 
SI addr1,addr2,instruction 
Search Program Memory in Symbolic Format from address1 to address2 for any  
occurrence of instruction. 
 
SM addr1,addr2,instruction 
Designated Format. (See SR command to set the radix.) Searches program memory  
from address1 to address2 for any occurrence of instruction. Specify  
instruction in the current radix. 
 
ZM address1,address2 
Zero the Program Memory from address1 to address2. 
 
 
Breakpoints 
 
B address 
Set Breakpoint. Sets breakpoint at address (symbolic address can be used). 
B FileReg {operator value} 
Set Breakpoint. Break when FileReg matches the condition given by the operator  
and the value. 
Valid operators: { = | > | < | > = | < = | ! = } 
 
BC 
Breakpoint Clear. Cancels all breakpoints. 
 
BC [addr|FileReg] 
Breakpoint Clear. Cancels breakpoint at addr or FileReg. 
 
DB 
Display All Active Breakpoints. 
Execution Instructions 
 
C [#breakpoints] 
Continue Executing. Continue execution ignoring #breakpoints encountered. 
 
E [address] 
Execute Program. Begins execution at the specified address, or at the current  
PC if address is omitted. The loaded program executes until reaching a  
breakpoint or until you press any key. 
 
GO 
Reset and Execute. Resets the microcontroller, initializes all registers  
and executes from the start. 
 
RS 
Reset Chip. Simulates a power-on reset. 
 
SS [address] 
Execute a Single Step. Executes a single instruction at the specified address  
or at the current PC if address is omitted.  To single step through multiple  
instructions, enter SS once and press <Enter> at the % prompt. Then continue  
pressing <Enter>. 
 
 
Tracing 
 
DX 
Display Current Trace Parameters. Displays the current trace parameters. In  
trace mode, the location, opcode, mnemonic, elapsed time, cycle steps, and  
changed file registers display when the given conditions are met. 
 
TA [address1,address2] 
Trace Address. Sets the lower validation limit for address trace to address1  
and the upper address validation limit to address2. With no arguments, MPSIM  
uses the full range of program memory. 
 
TC [#instructions] 
Trace Instructions. Trace the next  #instructions. If you omit #instructions,  
execution continues until MPSIM encounters a breakpoint or until you press  
any key. 
 
TF [filename|PRN] 
Trace to File/Printer. Open/Close trace output file or write trace to  
printer. With no argument, TF closes file. 
 
TR register [,min_val,max_val] 
Trace Register. Sets the file register trace. 
With no arguments, traces any file register. To perform trace only when  
register value lies between min_val and max_val, specify the min_val and  
max_val. 
 
 
Registers and Data Memory 
 
DR 
Display Registers. Displays the contents of special function registers  
including W, status, flags, and the stack. 
 
EE address 
Modify EE Memory. Modifies memory at the specified address on microcontrollers  
with EEPROM data memory. 
 
F FileReg 
File Register Display/Modify. Displays or modifies the contents of any FileReg  
(by absolute address or symbolic name). 
 
IR {ALL | RAM SFR} 
Initialize with Random Values. Loads random values into registers.  
 
LR [filename] 
Load Registers. Loads contents of registers with data from a DOS text file.  
 
SE [I/O_pin | port] 
Display/Modify I/O Pin. Displays or modifies an I/O_pin or port. 
 
UR {ALL|RAM|SFR}[filename] 
Upload Registers. Uploads contents of registers into a DOS text file.   
 
W 
Work Register Display/Modify. Displays/modifies the contents of the W register. 
 
ZR 
Zero the Registers. Zeros all file registers. 
Stimulus and Timer 
 
CK [pin,{#hi,#low|} 
Clock. Assigns a clock to specified I/O pin.                        
 CK                Displays current clock assignment. 
 CK pin,#hi,#low   Defines clock period on pin. 
 CK pin,-          Disables clock on specified pin. 
 
DK [AltFxkey#,[pin,event]|[]] 
Define Key. Assigns asynchronous event to an Alt function key. 
 DK                Displays assignment of all function keys 
 DK AltFxkey#      Displays assignment of specified function key   
 DK AltFxkey#,-    Cancels specified function.  
 DK, -             Cancels all assignments. 
event = H,L,T,P = High, Low, Toggle,  Pulse 
 
DW [E|D] 
Enable/Disable Watchdog Timer. 
E = Enable     D = Disable 
With no parameters, displays WDT state. 
 
FI {filename,addr,FileReg[,n]|} 
File Input. Inserts the next value from filename into file register when  
current PC=addr. Repeats n times. 
 
IP [time|step] 
Injection Point. Injects a stimulus according to the time or step count.  
With no parameters, displays current mode. 
 
RE 
Reset Elapsed Time and Step Count. 
 
SC [cyclelength] 
Display/Set Processor Cycle Time. Displays or modifies the microcontroller's  
simulated cycle time. 
 
ST filename 
Read Stimulus File. Loads stimulus file. 
 
Verbose [ON|OFF] 
Echo to View Screen. Prints a line to the view screen (and to the optional  
trace file) when a stimulus is injected into a pin. The command, without an  
argument, displays the current setting. 
 
WP {1 |...| 128} 
Watchdog Timer Period. Sets watchdog timer time-out period. With no  
parameters, displays current setting. Check the device AC characteristics  
table for typical twdt ranges.       
 
ZT 
Zero the Elapsed Time Counter. 
 
 
Program Memory Patch Control 
 
DP 
Display All Patches. Displays all patches in symbolic format. Both the  
original object code and new code are shown. 
 
RA 
Restore All. Restores patch table, clears symbol table and removes all  
breakpoints. 
 
RP 
Restore Patches. Restores all patches to original value and clears the  
patch table. 
 
ZP 
Zero the Patch Table. Clears patch table and resets to no patches made.  
Changes made to the object code are unaffected, and object code cannot be  
restored to the original. 
 
 
Symbol Table 
 
DL symbol 
Delete Symbol from Symbol Table. Removes specified symbol from the  
symbol table. 
 
DS 
Display Symbol Table. 
 
GS symbol, value, type 
Generate Symbol. Generates a symbol with the value and type specified. 
type: 
F - File Register 
B - Bit 
L - Label 
K - Literal 
 
LS filename 
Load Symbol File. Load filename into internal symbol table. 
 
 
View Screen 
 
AD FileReg[,radix[,#digits]] 
Add Item to View Screen. Use the AD command to add a display item to the  
view screen. 
The format of this command is identical to the V (View Screen) command.  
The AD command  
does not destroy the current contents of the view screen. 
 
DV FileReg 
Delete View Screen Item. Removes display items from the view screen, leaving  
the display formatting intact. 
 
NV 
No View Screen. Clear the view screen. The same effect can be achieved by  
redefining the view screen with V command. 
 
TY FileReg,radix,#digits 
Change View Screen. Change the formatting of the existing view screen. (If  
the designated signal isnt in the view screen, MPSIM gives a warning.) The  
radix can be x, o, d, or b. #digits is the number of spaces to reserve for  
this variable at display time. 
 
V FileReg[,radix[,#digits]] 
View Screen. Sets up the view screen. Once set, the view screen remains  
active until either a NV command or a V command sets up a new view screen.  
FileReg displays in radix mode with #digits. Radix defaults to hexadecimal  
and #digits to 1. The radix can be hexadecimal, octal, decimal or binary  
(x, o, d, or b). 
 
 
System Setup and Control 
 
EL {0 | 1 | 2} 
Error Level. Sets current error level. 
0 = Display All Messages  
1 = Display Warnings & Errors Only 
2 = Display Error Messages Only 
 
Enter EL with no parameters to display current level. 
 
FW {MC|EM|MP|RC256|RC64|RC|OSC} 
Fuse Word. Select microcontroller, extended microcontroller, or  
microprocessor operating mode, and set the watchdog timer fuse for the  
PIC17CXX simulator. Type FW with no parameters to display current modes.  
 
GE filename 
Get Commands from an External file. Forces MPSIM to read and perform the  
MPSIM commands in the named ASCII external file. Upon reaching the end of  
file, control returns to the user. 
 
LJ 
Load and Execute Journal File. 
 
P device# 
Select Microcontroller. Choose the appropriate microcontroller device#.  
The default is 55 which represents PIC16C55. 
device#= XX where xx is a 2-digit device suffix. 
 
SR {0|x|D} 
Set Radix. Sets the input/output radix to octal, hexadecimal,  
or decimal. The radix will be used on all inputs and outputs  
with the exception of step counts. 
 
 
Chapter 5.   MPSIM Commands 
The following table lists the commands currently available with MPSIM.  The  
sections that follow describe each command in greater detail.   
 
Press <RETURN> at the % prompt to re-execute the last command entered. Thus  
you can use commands such as SS more easily. 
 
Table 5.1  MPSIM Commands - Brief Alphabetical Listing  
[ ]   Brackets indicate optional items. 
{ }   Braces indicate group options. One or more options in the group is  
       required. 
 |    Vertical bar indicates alternative options. 
 
AB 
Abort Session. Aborts the dialogue, prints a summary message and exits to the  
operating system. AB does not overwrite the journal file. 
 
AD FileReg[,radix[,#digits]] 
Add Item to View Screen. Use the AD command to add a display item to the view  
screen. 
 
The format of this command is identical to the V (View Screen) command. The AD  
command does not destroy the current contents of the view screen. 
 
B address 
Set Breakpoint. Sets beakpoint at address (symbolic address can be used). 
 
B FileReg {operator value} 
Set Breakpoint. Break when FileReg matches the condition given by the operator  
and the value. 
      Valid operators: { = | > | < | > = | < = | ! = } 
 
BC 
Breakpoint Clear. Cancels all breakpoints. 
BC [addr|FileReg] 
Breakpoint Clear. Cancels breakpoint at addr or FileReg. 
 
C [#breakpoints] 
Continue Executing. Continue execution ignoring #breakpoints encountered. 
 
CK [pin,{#hi,#low|  - } 
Clock. Assigns a clock to specified I/O pin. 
 No Argument      Displays current clock assignment. 
 pin,#hi,#low     Defines clock period on pin. 
 pin,-            Disables clock on specified pin. 
 
DB 
Display All Active Breakpoints. 
 
DE address1,address2 
Delete Program Memory from address1 to address2. 
 
DI [address1[,address2]] 
Display Program Memory in Symbolic Format. Displays program memory from  
address1 to address2. Displays in current radix and symbolic format. Omit  
address2 to display next 10 lines from address1. 
 
DK [AltFxkey#,[pin,event]|[  - ]] 
Define Key. Assigns asynchronous event to an Alt function key. 
 DK               Displays assignment of all function keys. 
 DK AltFxkey#     Displays assignment of specified function key. 
 DK AltFxkey# -   Cancels specified function. 
 DK -             Cancels all assignments. 
     event = H,L,T,P = High, Low, Toggle, Pulse 
 
DL symbol 
Delete Symbol from Symbol Table. Removes specified symbol from the symbol  
table. 
 
DM [address1,address2] 
Display Program Memory in Radix Designated Format. (See SR command to set the  
radix.) Displays program memory from address1 to address2. Data displays in  
current radix only. With no parameter, displays 10 lines continuing from last  
DM display. 
 
DP 
Display All Patches. Displays all patches in symbolic format. Both the  
original object code and new code are shown. 
 
DR 
Display Registers. Displays the contents of special function registers  
including W, status, flags, and the stack 
DS 
Display Symbol Table. 
 
DV FileReg 
Delete View Screen Item. Removes display items from the view screen, leaving  
the display formatting intact. 
 
DW [E|D] 
Enable/Disable Watchdog Timer. 
  E = Enable     D = Disable 
With no parameters, displays WDT state. 
 
DX 
Display Current Trace Parameters. Displays the current trace parameters. In  
trace mode, the location, opcode, mnemonic, elapsed time, cycle steps, and  
changed file registers display when the given conditions are met. 
 
E [address] 
Execute Program. Begins execution at the specified address, or at the current  
PC if address is omitted. The loaded program executes until reaching a  
breakpoint or until you press any key. 
 
EE address 
Modify EE Memory. Modifies memory at the specified address on microcontrollers  
with EEPROM data memory. 
 
EL {0 | 1 | 2} 
Error Level. Sets current error level. 
      0 = Display All Messages 
      1 = Display Warnings & Errors Only 
      2 = Display Error Messages Only 
Enter EL with no parameters to display current level. 
 
F FileReg 
File Register Display/Modify. Displays or modifies the contents of any FileReg  
(by absolute address or symbolic name). 
 
FI {filename,addr,FileReg[,n]|  - } 
File Input. Inserts the next value from filename into file register when  
current PC=addr. Repeats n times. 
 
FM address1,address2,pattern 
Fill Memory. Fills program memory from address1 to address2 with specified HEX  
pattern. 
 
FW {MC|EM|MP|RC256|RC64|RC|OSC}  
Fuse Word. Select microcontroller, extended microcontroller, or microprocessor  
operating mode, and set the watchdog timer fuse for the PIC17CXX simulator.  
Type FW with no parameters to display current modes.  
 
GE filename 
Get Commands from an External file. Forces MPSIM to read and perform the MPSIM  
commands in the named ASCII external file. Upon reaching the end of file,  
control returns to the user. 
 
GO 
Reset and Execute. Resets the microcontroller, initializes all registers and  
executes from the start. 
 
GS symbol, value, type 
Generate Symbol. Generates a symbol with the value and type specified. 
type: F   -  File Register 
      B   -  Bit 
      L   -  Label 
      K   -  Literal 
 
H|Help|? 
Help. The Help Command lists the syntax and gives a brief summary of each  
command available in MPSIM. Press the SPACEBAR to exit Help. Press any other  
key to display the next help screen. 
 
IA address 
Insert/Inspect Assembly Code (Symbolic Format). Displays or modifies program  
memory at address using symbolic format. 
 
IN address,instruction 
Insert instruction. Inserts instruction at address in symbolic format. 
 
IP [time|step] 
Injection Point. Injects a stimulus according to the time or step count. With  
no parameters, displays current mode. 
 
IR {ALL | RAM SFR} 
Initialize with Random Values. Loads random values into registers.  
 
LJ 
Load and Execute Journal File. 
 
LO filename[format] 
Load Hex File. Loads the hex file, filename, with format into program memory.  
MPSIM also loads the listing file and symbol file. 
Valid Formats: INHX8M  (Default) 
               INHX8S 
 
LR [filename] 
Load Registers. Loads contents of registers with data from a DOS text file. 
 
LS filename 
Load Symbol File. Load filename into internal symbol table. 
 
M address 
Display/Modify Program Memory at Address. The contents at the address display,  
and a colon (:) prompt follows. To change the value at address, enter a new  
value (in the current radix) after the prompt. 
 
  Q         End the command 
  -         Cause MPSIM to go back to the previous address 
<Enter>     Continue to the next address 
 
NV 
No View Screen. Clear the view screen. The same effect can be achieved by  
redefining the view screen with V command. 
 
O filename [format] 
Output Modified Object Code. Writes contents of program memory, including  
modifications, to the specified file in the designated format. 
Valid Formats:   INHX8M  (Default) 
                 INHX8S 
                 INHX32 (for PIC17CXX) 
 
P device# 
Select Microcontroller. Choose the appropriate microcontroller device#. The  
default is 55 which represents PIC16C55. 
device# = XX where XX is a 2-digit device suffix. 
 
Q 
Quit. Terminates the dialog. Prints one or two summary messages, overwrites  
the old journal file and exits to the opening system. 
 
RA 
Restore All. Restores patch table, clears symbol table and removes all  
breakpoints. 
 
RE 
Reset Elapsed Time and Step Count. 
 
RP 
Restore Patches. Restores all patches to original value and clears the patch  
table. 
 
RS 
Reset Chip. Simulates a power-on reset. 
 
SC [cyclelength] 
Display/Set Processor Cycle Time. Displays or modifies the microcontroller's  
simulated cycle time. 
 
SE [I/O_pin | port] 
Display/Modify I/O Pin. Displays or modifies an I/O_pin or port. 
 
SF address1,address2,register 
Search Program Memory for Register. Searches program memory from address1 to  
address2 for any instruction that accesses the specified file register. 
 
SI addr1,addr2,instruction 
Search Program Memory in Symbolic Format from address1 to address2 for any  
occurrence of instruction. 
 
SM addr1,addr2,instruction 
Search Program Memory in Radix Designated Format. (See SR command to set the  
radix.) Searches program memory from address1 to address2 for any occurrence  
of instruction. Specify instruction in the current radix. 
 
SR {0|x|D} 
Set Radix. Sets the input/output radix to octal, hexadecimal, or decimal. The  
radix will be used on all inputs and outputs with the exception of step  
counts. 
 
SS [address] 
Execute a Single Step. Executes a single instruction at the specified address  
or at the current PC if address is omitted. 
To single step through multiple instructions, enter SS once and press <Enter>  
at the % prompt. Then continue pressing <Enter>. 
 
ST filename 
Read Stimulus File. Loads stimulus file. 
 
TA [address1,address2] 
Trace Address. Sets the lower validation limit for address trace to address1  
and the upper address validation limit to address2. With no arguments, MPSIM  
uses the full range of program memory. 
 
TC [#instructions] 
Trace Instructions. Trace the next #instructions. If you omit #instructions,  
execution continues until MPSIM encounters a breakpoint or until you press any  
key. 
 
TF [filename|PRN] 
Trace to File/Printer. Open/Close trace output file or write trace to printer.  
With no argument, TF closes file. 
 
TR register [,min_val,max_val] 
Trace Register. Sets the file register trace. With no arguments, traces any  
file register. To perform trace only when register value lies between min_val  
and max_val, specify the min_val and max_val. 
 
TY FileReg,radix,#digits 
Change View Screen. Change the formatting of the existing view screen. (If the  
designated signal isn't in the view screen, MPSIM gives a warning.) The radix  
can be x, o, d, or b. #digits is the number of spaces to reserve for this  
variable at display time. 
 
UR {ALL|RAM|SFR}[filename] 
Upload Registers. Uploads contents of registers into a DOS text file.  
 
V FileReg[,radix[,#digits]] 
View Screen. Sets up the view screen. Once set, the view screen remains active  
until either a NV command or a V command sets up a new view screen. FileReg  
displays in radix mode with #digits. Radix defaults to hexadecimal and #digits  
to 1. The radix can be hexadecimal, octal, decimal or binary (x, o, d, or b). 
 
Verbose [ON|OFF] 
Echo to View Screen. Prints a line to the view screen (and to the optional  
trace file) when a stimulus is injected into a pin. The command, without an  
argument, displays the current setting. 
 
W 
Work Register Display/Modify. Displays/modifies the contents of the W  
register. 
 
WP {1 |...| 128} 
Watchdog Timer Period. Sets watchdog timer time-out period. With no  
parameters, displays current setting. Check the device AC characteristics  
table for typical twdt ranges.    
 
ZM address1,address2  
Zero the Program Memory from address1 to address2. 
 
ZP 
Zero the Patch Table. Clears patch table and resets to no patches made.  
Changes made to the object code are unaffected, and object code cannot be  
restored to the original. 
 
ZR 
Zero the Registers. Zeros all file registers. 
 
ZT 
Zero the Elapsed Time Counter. 
 
 
 
AB   -  Abort Session 
Syntax: 
  AB 
 
Description: 
  The abort command interrupts the MPSIM session and exits.  It prints out one  
or two summary  messages, and exits to the operating system.  MPSIM retains  
the journal file. 
 
Examples: 
MPSIM Command   Result 
AB<RETURN>      MPSIM exits and displays the following message: 
                   Elapsed CPU time: h:mm:ss 
Defaults 
None. 
 
 
AD   -  Add Item to View Screen 
Syntax: 
  AD FileReg[,radix[,#digits]] 
 
Description: 
  The Add command adds a signal or register to the view screen.  Optionally,  
you may specify a radix different from the default and/or the number of  
digits. 
 
While this command's format is identical to View, it doesn't destroy the  
current contents of the view screen, but simply displays additional items as  
well as the current ones. 
 
Examples: 
MPSIM Command    Result 
AD IOA           Add Tris A to the screen. 
AD RA0,B         Add the RA0 pin to the screen display with binary radix. 
AD MCLR,4        Add MCLR pin to the screen display with 4 digits. 
AD F3,B,8        Add the F3 register (status) to the screen display with  
                  binary  radix and 8 digits. 
Defaults: 
Digits defaults to 2.  The radix ordinarily defaults to hexadecimal, but you  
can change this default with the SR command.  
Radix    Digits 
  X        2 
  B        8 
  O        3 
  D        2 
 
Related Commands 
The V command displays the first signal or register you request.   
Subsequently, you can add display items with AD or delete them with DV.  If  
you use a V command after AD, V replaces all previous display items on the  
screen with the named signal or register.  The NV command wipes all display  
items off the screen. 
 
The GE command can load an initialization file that sets up the view screen.   
Thereafter, you can use AD and DV to modify it. 
Note: When referencing registers for the AD instruction use hex  
notation.  For example, file register 10 would be written as 0A.   
Example: 
  AD F0A, X, 2 
 
 
B   -  Set Breakpoint 
Syntax: 
  B  address 
B  FileReg [operator value] 
 
Description 
This command sets a breakpoint at the specified address or at the location  
where the register matches the condition set by the operator and the value. 
You can designate the address either with the explicit numeric location or  
with a symbol. 
The operator can be any of the following: 
   =    equal 
   >    greater than 
   <    less than 
   >=   greater than or equal 
   <=   less than or equal 
   !=   not equal 
 
Examples: 
MPSIM Command         Result 
B LOOP<RETURN>        Set breakpoint at label LOOP. 
B F2 > 80<RETURN>     Break if F2 is greater than 80. 
 
Defaults 
None. 
 
Related Commands 
BC clears breakpoints previously set and DB displays them. 
Note: When referencing registers for relational instructions use decimal  
notation. 
 
 
BC   -  Clear Breakpoint 
Syntax: 
  BC  
BC  [addr | FileReg] 
 
Description 
This command deletes a specified breakpoint, or all breakpoints if you don't  
specify one by address or file register. 
 
Examples: 
MPSIM  Command       Result 
BC LOOP              Cancel breakpoint at LOOP. 
BC F3                Cancel breakpoint involving the F3 register. 
BC                   Cancel all breakpoints. 
 
Defaults 
None. 
 
Related Commands 
B sets breakpoints and DB displays them. 
 
 
C   -  Continue Executing 
Syntax 
C   [#breakpoints] 
 
Description: 
  This command continues execution from the current PC.  If you specify  
#breakpoints, MPSIM ignores the first #breakpoints breakpoints encountered. 
 
Examples: 
MPSIM Command        Result 
C                    Continue executing, break at the next breakpoint. 
C 3                  Continue executing, skip the first three breakpoints  
                      found, but break at the fourth. 
 
Defaults 
n defaults to 0. 
 
Related Commands 
B sets the breakpoints, DB displays them and BC clears breakpoints previously  
set. 
 
 
CK   -  Clock 
Syntax: 
  CK [pin,{#hi,#low|  - }] 
 
Description 
This command allows you to assign a clock to an I/O pin, defining the period  
of the clock by stating the number of cycles that the pin should be high, and  
the number of cycles that it should be low. 
 
No Argument   Displays current clock assignment. 
#hi           Defines the number of T-cycles that the pin should remain high 
#low          Defines the number of  T-cycles that the pin should remain low 
pin,-         Disables clock on specified pin. 
 
Examples: 
MPSIM  Command        Result 
% CK RC0, 5, 4        Assign a clock to RC0 with a 9 T-cycle period (5 high  
                       and 4 low cycles) 
% CK RC0, -           Cancel clock on RC0 
% CK                  Display current clock assignment 
 
Defaults 
None 
 
Related Commands 
None 
 
DB   -  Display All Active Breakpoints 
Syntax: 
  DB 
 
Description 
This command lists all active breakpoints.  MPSIM allows only one conditional  
breakpoint per data area. 
 
Examples: 
MPSIM Command        Result 
B LOOP               Sets a breakpoint at LOOP. 
B F2 > 80            Sets a breakpoint at the location where F2 >80. 
DB                   Displays all breakpoint locations via messages: 
                         INFO, Break when (F2 > 0080) 
                         INFO, Break on address LOOP 
Defaults 
None. 
 
Related Commands 
B sets the breakpoints, DB displays them and BC clears breakpoints previously  
set. 
 
 
DE   -  Delete Program Memory 
Syntax: 
  DE address1,address2 
 
Description 
This command deletes the information stored between address1 and address2,  
inclusively.  The DE command deletes memory within the given boundaries then  
shifts those locations in program memory that are greater than the upper bound  
down to the lower bound. 
 
Examples: 
MPSIM Command        Result 
DE 0015 0A10         This command removes the GOTO MAIN statement that causes  
                      the application to continuously execute. 
Defaults 
None. 
 
Related Commands 
None. 
 
 
DI   -  Display Program Memory in Symbolic Format 
Syntax: 
  DI [address1[, address2]] 
 
Description 
This command displays program memory in symbolic format from address1 to  
address2. address1 must be less then address2 and both must be in the valid  
range of program memory.  If no address2, then a screen full of lines displays  
from address1. 
 
You can terminate DI at any time by pressing any key at the terminal. 
 
Examples: 
MPSIM Command          Result 
DI  0, 3               The following messages display: 
                            0000    0020     MOVWF 0 
                            0001    0063     CLRF 3 
                            0002    0080     SUBWF 0, 0 
                            0003    0069     CLRF 9 
Defaults 
None. 
 
Related Commands 
The DM command also displays memory between two specified addresses; however,  
DM displays the code in the format specified by the current radix rather than  
in symbolic format. 
 
 
DK   -  Define Key 
Syntax: 
  DK   [AltFxKey#,[pin,event]|[  - ]] 
Description 
AltFxKey#        is an integer value between 1 and 12. 
AltFxKey#  -     Cancels specified function. 
Pin              is any valid I/O pin. 
Event            is H, L, T or P (high, low, toggle or pulse) 
  -              Cancels all assignments. 
No Argument      Displays assignments of all function keys. 
 
This command simulates an asynchronous event through an Alt-function keystroke  
and is very useful  for simulating external interrupts or resets. 
This function is used after a GO or E command. If you want to inject a  
stimulus while stopped at a breakpoint, use the SE command. 
 
In addition to the stated syntax, the following sequences perform the  
indicated operations. 
 
DK               Displays assignment of all function keys 
DK AltFxKey      Displays assignment of specified function key 
DK AltFxKey, -   Cancels specified function 
DK -             Cancels all assignments 
 
Examples: 
MPSIM Command          Result 
% DK 1,RB0,L      
% E                    When MPSIM is executing, if Alt-F1 is hit,  
                        RB0 will be driven low. 
% DK 12, MCLR, P       Define Alt-F12 to provide a one-cycle pulse  
                        on MCLR. 
% E                    Now during execution (with MCLR high) hitting  
                        Alt-F12 will simulate an external reset. 
% DK 3, RTCC, T        Define Alt-F3 to toggle RTCC input. 
% E                    Now during execution, every time Alt-F3 is pressed RTCC  
                        input will toggle.  
% DK -                 Disable all assignments. 
Defaults 
None 
 
Related Commands 
SE, ST 
 
DL   -  Delete Symbol from Symbol Table 
Syntax: 
  DL symbol 
Description 
This command removes the specified symbol from the symbol table. 
 
Examples: 
MPSIM Command      Result  
DL MULPLR          MPSIM removes mulplr from the symbol table.  To provide to  
                    or obtain data  from this data area, you must now use the  
                    actual register number, F10.  The value on the view  
                    screen, since it reads MULPLR isn't updated. 
Defaults 
None. 
 
Related Commands 
GS creates a symbol and puts it into the symbol table, LS loads a new symbol  
table, DS displays the current symbol table and RA restores (clears) the  
symbol table. 
 
DM   - Display Program Memory in Radix Designated Format 
Syntax: 
  DM [address1,address2] 
 
Description 
This command displays program memory from address1 to address2.  The data  
stored displays in the format designated by the current radix  address1 must  
be less than address2 and both must be in the valid range for program memory. 
You can terminate DM at any time by pressing any key on the terminal. 
 
Examples: 
MPSIM Command            Result 
DM 0, 3                  MPSIM displays the memory between locations 0 and 3. 
                          The following messages display: 
                            0000 0020 
                            0001 0063 
                            0002 0080 
                            0003 0069 
Defaults 
None. 
 
Related Commands 
The DI command also displays memory between two specified addresses; however,  
DI displays the code in symbolic format rather than in the format specified by  
the current radix. 
 
 
DP   -  Display All Patches 
Syntax 
DP 
 
Description: 
  This command displays all patches in symbolic format.  Both the original  
object code and new object code display. 
 
Examples 
MPSIM Command       Result 
DP 
Defaults 
None. 
 
Related Commands 
The M and IA commands modify the object code; .IN adds commands to the object  
code; DE removes object code; RA and RP restore the patches; and ZP zeros the  
patches.  The command, O, writes the modified object code as a hex file. 
 
 
DR   -  Display All Registers 
Syntax: 
  DR 
 
Description 
This command displays the contents of all registers including the W and status  
registers, all flags and the stack. 
Defaults 
None. 
 
Related Commands 
The DP, DS, and DX commands display other MPSIM data areas and parameters. 
SE sets any data area's value.  W displays and optionally modifies the W  
register.   
 
F displays and optionally modifies a register value. 
 
 
DS   -  Display Symbol Table 
Syntax: 
  DS 
 
Description 
This command displays the symbol table. 
 
Examples: 
MPSIM Command     Result 
DS                The following messages display: 
                        Symbol Value Type 
                       START    0000  L 
Defaults 
 
None. 
 
Related Commands 
GS creates a symbol and puts it into the symbol table, LS loads a new symbol  
table, DL removes a symbol from the current symbol table and RA restores  
(clears) the symbol table. 
 
 
DV   -  Delete View Screen Item 
Syntax: 
  DV FileReg 
 
Description: 
  This command removes display items from the view screen while leaving the  
display formatting intact. 
This command deletes a signal or register from the view screen display. 
 
Examples: 
MPSIM Command         Result 
DV RTCC               Deletes the RTCC from the view screen. 
Defaults 
None. 
 
Related Commands 
The V command displays the first signal or register you request.   
Subsequently, you can add display items with AD or delete them with DV.  If  
you use a V command after AD, V replaces all previous display items on the  
screen with the named signal or register.  The NV command wipes all display  
items off the screen. 
 
The GE command can load an initialization file that sets up the view screen.   
Thereafter, you can use AD and DV to modify it. 
 
 
DW   -  Enable / Disable  Watchdog Timer 
Syntax: 
  DW [E|D] 
Description 
This command enables or disables the watchdog timer, depending or the  
parameter specified.  E enables it; D disables it. 
 
Examples: 
MPSIM Command       Result 
DW E                Enables the watchdog timer. 
DW D                Disables the watchdog timer. 
 
Defaults 
None. 
 
Related Commands 
RE resets the elapsed time and step count and ZT zeros the elapsed time. 
 
 
DX   -  Display Current Trace Parameters 
 
Syntax: 
  DX 
 
Description 
This command displays the current trace parameters.  When in trace mode, the  
location, opcode, mnemonic, elapsed  time, cycle steps, and any changed data  
areas display when the given conditions are met. 
 
Examples: 
MPSIM Command      Result 
DX                 The following message displays: 
                      Address     0000:01FF 
 
Defaults 
None. 
 
Related Commands 
The TA, TC and TR commands set the trace parameters. 
 
 
E   -  Execute Program 
Syntax 
E [address] 
 
Description: 
  This command executes the program from the optionally specified address or  
the PC. 
The E command begins execution at the specified address or at the current  
address if no address is specified.  The program continues to execute until  
either reaching a breakpoint or until you press a key. 
 
Examples: 
MPSIM Command     Result 
E 0E              MPSIM executes SAMPLE.HEX from the label START until  
                   reaching a breakpoint or until you press any key. 
 
Defaults 
None. 
 
Related Commands 
The GO command resets then executes from the start; SS executes the  
instruction at the current PC or at a specified address.  C executes from the  
current PC to the specified breakpoint occurrence.  TA traces execution  
between specified addresses, and TC traces execution from the current PC for a  
specified number of instructions. 
 
 
EE   -  Modify EE Memory 
Syntax: 
  EE address 
Description 
Manually Modify EE memory address on the PIC16C84. 
 
Examples: 
MPSIM Command        Result 
% EE 2               EEMEMORY[2]:00: 23 
                     EE memory location 2 now contains value 0x23. 
Defaults 
None. 
 
 
EL   -  Error Level 
Syntax: 
  EL  {0 | 1 | 2} 
 
Description: 
  This command sets the current level for displaying error messages and system  
warnings. 
  0 = Display All Messages 
  1 = Display Warnings and Errors Only 
  2 = Display Error Messages Only 
Enter EL with no parameters to display current level. 
 
Examples: 
MPSIM Command       Result 
% EL 0              All messages will display. 
% EL 1              Only warnings and Error messages will display. 
% EL 2              Only error messages will display. 
% EL                Current warning level will display. 
 
Defaults 
All messages are displayed (Error level of 0). 
 
Related Commands 
None 
 
 
F   -  File Register Display/Modify 
Syntax: 
  F FileReg 
 
Description 
This command displays and/or modifies the contents of the specified file  
register.  The value of the register displays, followed by the prompt :'.   
Place the new value after the prompt. 
 
Examples: 
MPSIM Command       Result 
% F3                The following message displays: 
                       3:  20: 
                    This message shows that file register 3 contains the  
                       value 20.' 
% F3                  3: 20: 21 
 
Change file register 3 to a value of 21.' 
Defaults 
None. 
 
Related Commands 
The SE command can give the same result.  DR, TR and ZR display, trace and  
zero a specified register, respectively.  M and IA modify the code at a  
specified address, which can affect the register's value. 
 
 
FI   -  File Input 
Syntax: 
  FI {filename,addr,FileReg[,n]|  - } 
 
Description 
This command inserts the next value from filename into file register when  
current PC=addr.  If n is not specified, when the last value in the file is  
read,  the next retrieved value will be the first value in the file.  This  
will continue until the command is cancelled. If n is specified then the file  
will be read n times only. 
 
FileName  
is any valid DOS file name. The file should be an ASCII file and should  
contain one hex value per line. 
 
PMemAddr 
is the point in program memory at which value should be injected. 
 
FRegAddr  
File register that receives the value. 
 
n 
Number of times to go through the file. 
 
FI -   
Closes file and cancels command. 
 
Examples: 
MPSIM Command             Result 
% FI ADVAL.TXT, 4,9       When the PC=4, insert the next value from ADVAL.TXT  
                           into register 9. 
% FI -                    Close file and cancel assignment. 
 
The FI command is useful when simulating devices such as the PIC16C71 and  
PIC16C74. Both of these devices have A/D converters (among other peripheral  
modules). MPSIM does not perform an A/D conversion, although the interrupt  
that can be generated upon its completion is supported in the software. The FI  
command allows you to inject values into a register when a certain point in  
program memory is reached. For example, if the target processor is the  
PIC16C71, you could set up your source code to branch to the interrupt vector  
at the end of conversion and inject a value into the ADRES register during the  
interrupt service routine (by using the FI command). 
 
The command could be set up as follows: 
    FI    ADVAL.TXT,     0x04 0x09 
When the Program Counter equals the interrupt vector (program memory address  
0x04), inject the next value in the file (ADVAL.TXT) into the ADRES register  
(file register address 0x09). 
 
            org 0x04 
IntVct      bcf INTCON, ADIE      ;At this point, the next  
            movfw ADRES           ;value in ADVAL.TXT will 
                                  ;be in the ADRES register 
    -   
    -   
    -   
The format of the ADVAL.TXT file is one HEX value on each line. For example: 
0xAA 
0X55 
0XAA 
0X55 
and so on. 
Defaults 
None. 
 
Related Commands 
None. 
 
 
FM   -  Fill Memory 
Syntax: 
  FM address1,address2,pattern 
Description 
This command fills unused program memory between address1 and address2 with  
the specified HEX pattern. 
 
Examples: 
MPSIM Commands         Result 
% FM 0,30,0xFFF        Fill unused program memory between 0 and 30 with 0xFFF. 
 
Defaults 
None. 
 
Related Commands 
M 
 
 
FW   -  Fuse Word 
Syntax: 
  FW {MC|EM|MP|RC256|RC64|RC|OSC} 
 
Description: 
  This command selects the operation mode (Microcontroller Mode, Extended  
Microcontroller Mode, and Microprocessor Mode) or the WDT prescale option for  
processors in the PIC17CXX family only (these options are hardware fuse- 
selectable only on the physical device). 
   MC = Microcontroller Mode 
   EM = Extended Microcontroller Mode 
   MP = Microprocessor Mode 
 
Type FW with no parameters  to display current modes. 
 
Examples: 
MPSIM Command      Result 
% FW MC            Processor will run in Microcontroller Mode 
% FW RC64          WDT will have a prescale = 64 
% FW               Current operation mode and WDT prescale option are  
                    displayed. 
 
Defaults 
Operation mode = Microprocessor 
WDT Prescale = OSC 
 
Related Commands 
None. 
 
 
GE   -  Get Commands from an External File 
Syntax: 
  GE filename 
 
Description 
This command reads and performs the MPSIM commands in the named ASCII file. 
This command forces MPSIM to get its command stream from an external text  
file.  After reaching the end of file, control returns to the user.  Commands  
in the text file must conform to the same syntax as commands entered on-line.   
If MPSIM cannot locate the specified file, an error message displays. 
 
Examples: 
MPSIM Command        Result 
GE SAMPLE.INI        Reads and performs commands in the file, SAMPLE.INI. 
 
Defaults 
None. 
 
Related Commands 
The V command displays the first signal or register you request.   
Subsequently, you can add display items with AD or delete them with DV.  If  
you use a V command after AD, V replaces all previous display items on the  
screen with the named signal or register.  The NV command wipes all display  
items off the screen. 
 
The GE command can load an initialization file that sets up the view screen.   
Thereafter, you can use AD and DV to modify it. 
 
 
GO   -  Reset and Execute 
Syntax: 
  GO 
Description 
This command performs a Power-On Reset and initializes all registers as  
specified in the microcontroller data sheet. The PIC16/17 Microcontroller then  
executes the loaded object code. 
 
Examples: 
MPSIM Command     Result 
GO                Reset and execute. 
 
Defaults 
None. 
 
Related Commands 
The E command executes from a specified address or the current PC; SS executes  
the instruction at the current PC or at a specified address.  C executes from  
the current PC to the specified breakpoint occurrence.  TA traces execution  
between specified addresses, and TC traces execution from the current PC for a  
specifies number of instructions. 
 
 
GS   -  Generate Symbol 
Syntax 
GS symbol,value,type 
Description 
This command generates the specified symbol with the specified value and type.   
The type can be file(F), bit(B), label(L), or literal(K).  If the type is bit,  
it is a bit in the specified file. 
 
Examples: 
MPSIM Command      Result 
% DS                Symbol   Value      Type 
                    START     0000        L 
% GS NEWSYM, FF, B 
% DS                Symbol   Value      Type 
                    START     0000        L 
                    NEWSYM      FF        B 
Defaults 
None. 
 
Related Commands 
DL removes a symbol from the current symbol table, LS loads a new symbol  
table, DS displays the current symbol table and RA restores (clears) the  
symbol table. 
 
 
H   -  Help 
Syntax: 
  H | Help | ? 
 
Description 
This command lists the syntax and gives a brief summary of each command  
available in MPSIM. Press the SPACEBAR to exit Help. Press any other key to  
display the next help screen.   
 
Examples: 
MPSIM Command    Result 
H                The Help screen, containing command descriptions and syntax  
                  displays. 
 
Defaults 
None. 
 
Related Commands 
None. 
 
 
IA   -  Insert/Inspect Assembly Code 
Syntax: 
  IA address 
 
Description 
This command displays or modifies the program memory at address in symbolic  
format.  The source code for the address displays, followed by the prompt ':'  
on the next line for the new command. 
 
Enter the new command as a mnemonic.  It must be syntactically correct.   
Operands may contain only a single value or symbol; expressions are not  
allowed.  Enter values in the current radix. 
 
Entering 'Q' at the prompt ends the command; entering '-' causes MPSIM to go  
back and inspect and/or modify the previous address; entering <RETURN>  
continues to the next address. 
After changing the object code, MPSIM no longer displays the original source  
code.  MPSIM replaces it with a disassembled source line. 
 
Examples 
MPSIM Command          Result 
% IA 200<RETURN>       The instruction line at address 200 (in current radix)  
                        displays: 
                           0020   :   CLRF F5 
                                  :   CLRF 6 
                       MPSIM changes the instruction  as specified and  
                        displays the next instruction line (address 201): 
                           0201   :   CLRF F7: 
                                  :   - 
                       MPSIM backs up and displays the modified instruction at  
                        address 200: 
                           0200   :   CLRF 6: 
                                  :   Q 
                       MPSIM exits the IA command. 
 
Defaults 
None. 
 
Related Commands 
DE, IN, M 
 
 
IN   -  Insert Instruction 
Syntax: 
  IN address,instruction 
 
Description 
This command inserts instruction at address.  The instruction places an opcode  
at address then displaces each program memory value after address by one  
location.  instruction must consist of a valid mnemonic followed by zero or  
more operands.  Each operand must contain a single value or symbol, no  
expressions are allowed. 
 
Examples: 
MPSIM Command         Result 
% IN 200, NOP         MPSIM inserts a NOP instruction at address 200 (in the  
                       current radix). 
 
Defaults 
None. 
 
Related Commands 
DE, IA, M 
 
 
IP   -  Injection Point  
Syntax: 
  IP [time|step] 
 
Description: 
  Inject stimulus according to time or step count.  The step heading should  
remain labeled as step in the stimulus file, but IP TIME will override this  
setting. If IP is typed with no parameters, the current mode (TIME or STEP)  
will be shown. With no parameters, displays current mode. 
 
Examples 
MPSIM Command        Result 
% IP time            Stimulus will now be injected according to time (integer  
                      values only). 
 
Defaults 
Default is "step" 
 
Related Commands 
None. 
 
 
IR   -  Initialize with Random Values 
Syntax: 
  IR {ALL | RAM SFR} 
 
Description: 
  Loads random values into registers. 
 
Examples: 
MPSIM Command      Result 
% IR ALL           All registers will be initialized with random values 
% IR RAM           Only general-purpose registers will be initialized with  
                    random values 
 
Defaults 
ALL file registers will be loaded with random values. 
 
Related Commands 
UR, LR 
 
 
LJ   -  Load and Execute Journal File  
Syntax: 
  LJ 
Description 
This command loads and executes the journal file commands.  These commands are  
not stored in the journal file recorded from the current session; MPSIM enters  
only the LJ command. 
 
When the journal file contains a program execution command, you must press a  
key to stop program execution or wait until a breakpoint break occurs; the  
journal file doesn't record premature execution breaks or exits. 
 
Examples: 
MPSIM Command          Result 
% LJ                   All MPSIM commands entered during the previous MPSIM  
                        session execute.  These commands are not stored in the  
                        journal file recorded from the current session. 
 
Defaults 
The default extension is .JRN. 
 
Related Commands 
GE, LJ, LO, ST 
 
 
LO   -  Load Object File 
Syntax: 
  LO filename {format} 
 
Description: 
  This command loads the specified file into program memory.  If the selected  
assembler is MPASM, MPSIM will assume a .HEX extension.  After loading the HEX  
file, MPSIM attempts to load the listing file using the same filename and the  
extension .LST'.  If MPSIM cannot find the listing file then all instruction  
displays will be a disassembly.  When found, MPSIM uses the listing file for  
display throughout simulation. 
 
The following is a list of valid formats: 
     INHX8M 
     INHX8S 
 
Examples: 
MPSIM Command         Result 
% LO SAMPLE           The HEX, listing and symbol file are loaded into MPSIM  
                       in INHX8M format. 
% LO SAMPLE INHX8S    The HEX, listing and symbol file are loaded into MPSIM  
                       in INHX8S format. 
 
Defaults 
The default extension is .HEX' and the default format is INHX8M. 
 
Related Commands 
GE, LJ, LS, ST 
 
 
LR   -  Load Registers 
Syntax: 
  LR filename 
 
Description: 
  This command loads the contents of registers with data from a DOS text file. 
This command loads each file register listed on each row of  filename with the  
specified value.  If no file name is supplied, MPSIM searches for a file  
called ram.dat.   Each line in the file should consist of the Bank Number,  
File Register Number, and Value as follows: 
    BankNumber : FileRegisterNumber , Value 
 
This format is also used with the UR - Upload Registers command.  The  
following sample is an excerpt from a ram.dat file: 
                 ;File register values for myfile.asm 
    0, 0F, 0F 
    0, 10, AA 
    0, 17, FF 
 
All values should be in hexadecimal radix and should begin in the first column  
of each row.  Blank lines or lines beginning with ; or ! will be interpreted  
as  comment lines and will be ignored.   If an error is found in the file, a  
warning message will be displayed and the offending line will be ignored. 
 
Examples: 
MPSIM Command       Result 
% LR                File registers in RAM.DAT will be loaded with specified  
                     value 
% LR myfile         File registers in myfile will be loaded with specified  
                     value. 
 
Defaults 
Registers and values from ram.dat file are loaded. 
 
Related Commands 
UR, IR 
 
 
LS   -  Load Symbol File 
Syntax 
LS filename 
 
Description: 
  This command loads the specified symbol file into the internal symbol table.   
 
If symbolic debugging, the symbol file produced by the assembler must be  
loaded with the LS command or loaded through the LO command. 
 
Examples: 
MPSIM Command        Result 
% LS SAMPLE          MPSIM reads in the symbol file SAMPLE. 
 
Defaults 
The default extension is .SYM. 
 
Related Commands 
GS, DL, DS, RA 
 
 
M   -  Display / Modify Program Memory at Address 
Syntax 
  M address 
 
Description 
This command displays and/or modifies program memory at address.  The contents  
of the address display in the radix designated format, and are followed  
immediately by a prompt ':'. 
 
To change the value at address, place a new value after the prompt.  Be sure  
to enter that value in the current radix.   
 
Entering 'Q' at the prompt ends the command. 
Entering '-' causes MPSIM to go back and inspect and/or modify the previous  
             address. 
Entering <RETURN> continues to the next address. 
 
Examples: 
MPSIM Command        Result 
% M 0005             MPSIM displays the instruction line at address 0005 (as  
                      determined by the current radix) in the current radix: 
% SR O  
% M 010              MPSIM sets the radix to octal, then displays the  
                      instruction line at the label MAIN in octal. 
% Q                  MPSIM exits the M command. 
% SR X 
% M 010              MPSIM sets the radix to hexadecimal, then displays the  
                      instruction line at the label MAIN in hexadecimal. 
: -                  MPSIM redisplays the instruction line at MAIN. 
% SR D 
% M main             MPSIM sets the radix to decimal, then displays the  
                      instruction line at the label MAIN in decimal. 
 
Defaults 
None. 
 
Related Commands 
IA 
 
 
NV   -  No View Screen 
Syntax 
NV 
Description 
This command deletes or clears all elements  from the view screen. 
The same effect can be achieved by redefining the view screen. 
 
Examples: 
MPSIM Command        Result 
% NV                 MPSIM removes all items from the view screen. 
 
Defaults 
None. 
 
Related Commands 
AD, V 
 
 
O   -  Output Modified Object Code 
Syntax 
  O filename [Format] 
 
Description 
This command writes the contents of program memory, including any  
modifications to the specified file in the specified format.  The program  
memory contains object code. 
 
The following is a list of valid formats: 
         INHX8M 
         INHX8M 
         INHX8S 
         PICICE 
 
Examples 
MPSIM Command               Result 
% O SAMPLE1.HEX INHX8M      MPSIM writes the object code, as modified, to the  
                             file SAMPLE1.HEX in the INHX16 format. 
 
Defaults 
Default output format is the same as the default input format, INHX8M. 
 
Related Commands 
None. 
 
 
P   -  Select Microcontroller  
Syntax: 
  P device# 
Description 
Use this command to choose the appropriate microcontroller device#. The  
default is 55 which represents PIC16C55. 
device#   = XX where XX is a 2-digit device sufix. 
 
Examples: 
MPSIM Command      Result 
% P 71             MPSIM sets the processor type to PIC16C71. 
 
Defaults 
The simulated microcontroller defaults to 55. 
 
Related Commands 
None. 
 
 
Q   -  Quit 
Syntax: 
  Q 
 
Description: 
  This command exits from MPSIM and returns PC control to DOS.  MPSIM stores  
all MPSIM commands entered during this session in the journal file, MPSIM.JRN.   
The old MPSIM.JRN, if present, is overwritten. 
 
Examples: 
MPSIM Command     Result 
% Q               MPSIM exits and displays the following message: 
                      Elapsed CPU time: h:mm:ss. 
 
Defaults 
None. 
 
Related Commands 
AB 
 
 
RA   -  Restore All 
Syntax: 
  RA 
 
Description 
This command restores the patch table, clears the symbol table of user defined  
symbols and removes all breakpoints. 
 
Examples: 
MPSIM Command      Result 
% RA               MPSIM restores the patch table, clears the symbol tables  
                    and removes all breakpoints. 
 
Defaults 
None. 
 
Related Commands 
RP, DL, BC 
 
 
RE   -  Reset Elapsed Time and Step Count 
Syntax: 
  RE 
 
Description: 
  This command resets the elapsed time and the step count to zero. 
 
Examples: 
MPSIM Command       Result 
% RE                MPSIM resets the elapsed time and the step count to zeros. 
 
Defaults 
None. 
 
Related Commands 
ZT 
 
 
RP   -  Restore Patches 
Syntax: 
  RP 
 
Description: 
  This command restores all patches to their original value and clears the  
patch table. 
 
Examples: 
MPSIM Command      Result 
% RP               MPSIM restores all patches. 
 
Defaults 
None. 
 
Related Commands 
RA 
 
 
 
RS   -  Reset Chip 
Syntax: 
  RS 
 
Description: 
  Performs a Power-On Reset and initializes all registers as specified in the  
data sheet of the specified microcontroller. 
 
Examples: 
MPSIM Command      Result 
% RS               Executes a Power-On-Reset. 
 
Defaults 
None. 
 
Related Commands 
GO 
 
 
SC   -  Display / Modify Processor Cycle Time 
Syntax: 
  SC [cyclelength] 
Description 
This command displays and/or modifies the microcontroller's simulated cycle  
time. 
 
Examples: 
MPSIM Command     Result 
% SC              MPSIM displays the current cycle in ms: 2.0: 
    2.0:.2        The entry .2' changes the cycle to .2ms, or 200 ms. 
% SC 2000.0       The cycle length is changed to 2000.0ms or 2.0 ms. 
 
Defaults 
The simulated cycle time defaults to 2 microseconds. 
 
Related Commands 
None. 
 
 
SE   -  Display / Modify I/O Pin 
Syntax: 
  SE [I/O_pin | port] 
Description 
This command displays or modifies an I/O_pin or port. 
 
Examples: 
MPSIM Command    Result 
% SE RA0         The following message displays:  RA0=1: 
      RA0:1:0    The value of I/O pin RA0 changes from 1 to 0. 
 
Defaults 
None. 
 
Related Commands 
F, W, ZR 
 
 
SF   -  Search Program Memory for Register 
Syntax: 
  SF address1,address2,register 
 
Description 
This command searches program memory from address1 to address2  for any  
instruction that access the specified register.  Register may be specified in  
literal, F' syntax or as a symbol. 
 
Examples: 
MPSIM Command      Result 
SF 0, 22, portb    MPSIM search all memory from 0 through 22 for instructions  
                    that reference the portb register, then displays the lines  
                    containing the specified instruction 
0000 0000    main movf portb,W 
0006 0000    movf portb,W 
 
Defaults 
None. 
 
Related Commands 
SI, SM 
 
SI   -  Search Program Memory in Symbolic Format 
Syntax: 
  SI address1,address2,instruction 
 
Description: 
  This command searches program memory from address1 to address2 for any  
occurrence of instruction.  instruction is in symbolic format.  Full or  
partial instructions may be specified. 
 
Examples 
MPSIM Command        Result 
% SI 0, 20, CLRF     MPSIM searches all memory from 0 through 20 for CLRF  
                      instructions, then displays the lines containing the  
                      specified instruction: 
                          0000  mpy_S  clrf H_byte 
                          0001  clrf  L_byte 
% SI 0, 20,           MPSIM searches all movwf count memory from 0 through 20  
                       for  MOVWF COUNT instructions, then display the lines  
                        containing the specified instruction: 
                          0003    movwf    count 
 
Defaults 
None. 
 
Related Commands 
SF, SM 
 
 
SM   -  Search Program Memory in Radix Designated Format 
Syntax 
SM address1,address2,instruction 
 
Description 
This command searches program memory from address1 to address2 for  
instruction.  Specify instruction in the format designated by the radix.  
 
Examples: 
MPSIM Command        Result 
% SM 0, 30, C08      MPSIM search all memory from 0 through 20 for the  
                      specified instruction, then displays, in the current  
                       radix, the lines containing it: 
                            0002  movlw  8 
 
Defaults 
None. 
 
Related Commands 
SF, SI 
 
 
SR   -  Set Radix 
Syntax: 
  SR [O|X|D] 
 
Description 
This command sets the radix to octal, hexadecimal or decimal.  Subsequently,  
MPSIM expects and uses this radix for all I/O including file register numbers  
and step counts. 
 
Examples: 
MPSIM Command     Result 
% SR O            The radix becomes octal. 
% SR X            The radix becomes hexadecimal. 
% SR D            The radix becomes decimal. 
 
Defaults 
None. 
 
Related Commands 
None. 
 
 
SS   -  Execute A Single Step 
Syntax: 
  SS [address] 
 
Description 
This command executes a single step located at address.  If you don't specify  
address, MPSIM executes the instruction at the current PC.  Pressing <RETURN>  
at the % prompt re-executes the previous MPSIM command.  Thus, by entering SS  
once and subsequently pressing simply <RETURN>, you can single step through  
multiple instructions easily. 
 
Examples: 
MPSIM Command      Result 
% SS 01FF          MPSIM resets the simulator code by executing the reset  
                    address (PIC16C54 and PIC16C55). 
% SS               MPSIM executes the line of code at the PCP. 
% SS 20            MPSIM executes the line of code at address 20 (in the  
                    current radix). 
% SS LOOP          MPSIM executes the line of code at the label LOOP. 
 
Defaults 
None. 
 
Related Commands 
None. 
 
 
ST   -  Read Stimulus File 
Syntax: 
  ST filename 
 
Description 
This command inserts specified values into specified pins or registers at a  
specified simulation step or time.  The specified values, pins/registers and  
steps are defined in a text file called a stimulus file.  Stimulus can be  
injected either according to step or time.  See instruction IP' for details. 
The stimulus file allows you to schedule bit manipulation by forcing MPSIM to  
drive given pins to given values at a specified input step. 
 
The ST command reads the stimulus file into MPSIM.  When you execute a file  
with the E command, each time it looks for input, it reads the next step in  
the stimulus file. 
 
The first line of stimulus file always consists of column headings.  It lists  
first the word STEP, followed by the pins that are to be manipulated.  The  
data below STEP represents the object file's input request occurrence.  The  
data below each pin name is the input value.  You may enter comments at the  
end of a line by preceding it with an exclamation mark (!). 
The following example illustrates the stimulus file format: 
STEP    RA0    RA1       ! These are I/O pin names 
  8      1      0 
 16      0      1        ! followed by values 
 24      1      1 
 
Other notes on the format of stimulus file: 
   -  the number of spaces separating columns is irrelevant 
   -  the step count must be in decimal 
 
Examples: 
MPSIM Command      Result 
% ST SAMPLE.STI    MPSIM reads the specified stimulus file.  Upon execution,  
                    it will retrieve input as designated in this file. 
 
Defaults 
The default injection point is step.  The default file extension is .STI'. 
 
Related Commands 
IP 
 
 
TA   -  Trace Address 
Syntax: 
  TA [address1,address2] 
 
Description 
This command sets the trace to print only those instructions located between  
address1 and address2.  If you don't specify address1 and address2, MPSIM uses  
the full memory. 
 
Examples: 
MPSIM Command         Result 
% TA main, call_m     MPSIM will print/display only those instructions between  
                       main and call_m.  
 
Defaults 
Address range defaults to all of memory. 
 
Related Commands 
TC, TF, TR 
 
 
TC   -  Trace Instructions 
Syntax: 
  TC [#instructions] 
 
Description: 
  This command traces the next #instructions instructions, displaying the  
instructions if they are valid.  If you don't supply the #instructions, the  
trace continues indefinitely until encountering a breakpoint or until you  
press any key. 
 
Examples: 
MPSIM Command      Result 
% TC 3             Trace the next three instructions. 
 
Defaults 
None. 
 
Related Commands 
TA, TF, TR 
 
 
TF   -   Trace to File/Printer 
Syntax: 
  TF [filename | Prn] 
 
Description 
This command opens or closes a file for writing the trace, or prints the  
trace.  If you enter PRN as an argument, MPSIM prints the trace to the default  
printer.  If you supply filename, MPSIM opens that file, if you don't, MPSIM  
closes any currently opened output trace file. 
 
You must use the TF command BEFORE starting the trace. 
 
Examples: 
MPSIM Command    Result 
% TF             Close the output trace file. 
% TF PRN         Print the trace to the default printer. 
% TF SAMPLE.TRC  Open SAMPLE.TRC and write the trace to it. 
 
Defaults 
None. 
 
Related Commands 
TA, TC, TR 
 
 
TR   -  Trace Register 
Syntax 
TR register [,min_val,max_val] 
 
Description 
This command sets the file register trace.  If you don't supply any  
parameters, MPSIM traces any file register.  If you specify register, it  
traces that register.  If you also specify min_val and max_val, it performs  
the trace only if the value of the specified register lies between min_val and  
max_val. 
 
Examples: 
MPSIM Command      Result 
% TR               Traces all registers. 
% TR W             Traces the W register. 
% TR W, 2, 7       Traces the W register when its value falls between 2 and 7  
                    (in the current radix). 
 
Defaults 
None. 
 
Related Commands 
TA, TC, TF 
 
 
TY   -  Change View Screen 
Syntax: 
  TY FileReg,radix,#digits 
 
Description 
This command changes the formatting of the existing viewscreen. (If the  
designated signal isn't in the viewscreen, MPSIM gives a warning.) 
The radix can be hexadecimal, octal, decimal or binary, designated by X, O, D  
or B, respectively. 
 
#digits is the number of spaces to reserve for this variable at display time. 
 
Examples: 
MPSIM Command      Result 
% TY RTCC,B,1      RTCC I/O pin displays in binary, using one digit. 
 
Defaults 
None. 
 
Related Commands 
AD, NV, V 
 
 
UR   -  Upload Registers 
Syntax: 
  UR {ALL|RAM|SFR}filename 
 
Description: 
  This command uploads the contents of registers into a DOS text file. 
This command uploads file registers to filename (or  to the default file name  
ram.dat if no file name is specified).  The file will be in ASCII format and  
will consist of multiple lines in the following format: 
    BankNumber: FileRegisterNumber, Value 
 
All values will be in hexadecimal radix and will begin in column one.  For  
example, if ALL registers are to be uploaded to a file, the special-function  
registers would be print first, then all of the general-purpose registers  
would be printed:       
                      ;Special Function Registers 
  0, 00, 00 
  0, 01, 09 
  0, 02, B1 
 
Examples: 
MPSIM Command    Result 
% UR ALL         Upload all registers to file RAM.DAT 
% UR SFR t.out   Upload all special-function registers to the file t.out 
 
Defaults 
None. 
 
Related Commands 
LR, IR 
 
 
V   -  View Screen 
Syntax 
V FileReg[,radix[,#digits]] 
This command creates a new view screen that displays the named signal or  
register.  Optionally, you may specify a radix different from the default  
and/or a number of digits. 
 
V sets up the view screen.  This means that the View command defines  
the variables (and respective formats) to constantly display on the screen.   
Once the view screen is set, it remains active until either an NV command or  
a V command sets up a new view screen.  The format of this command 
is relatively simple.  FileReg displays in radix mode with #digits. Radix  
defaults to hexadecimal and #digits to 1. The radix can be B (binary),  
O (octal), X (hexadecimal) or D (decimal). 
 
Examples: 
MPSIM Command       Result 
% V F3,b,8          A view screen element is created with the following  
                     format: 
                       F3: 00000000 
% V RB0             A view screen element is created with the following  
                     format: 
                      RB0: 00 
 
Defaults 
The radix ordinarily defaults to hexadecimal, but you can change this default  
with the SR command.  Digits defaults according to the table below: 
 
Table 5.2 radix default widths 
Radix    Digits 
  X        2 
  B        8 
  O        3 
  D        2 
 
Related Commands 
AD, DV, NV, TY 
 
 
Verbose   -  Echo to Screen 
Syntax: 
  Verbose [ON|OFF] 
 
Description: 
  Prints a line to the screen (and to the optional trace file) when stimulus  
is injected into a pin.  The command, without an argument, displays the  
current setting. 
 
Examples: 
MPSIM Command     Result 
% VERBOSE ON      Print to screen when stimuli are simulated. 
 
Defaults 
None. 
 
Related Commands 
  -   -   -   -   -  
 
 
W   -  Work Register Display / Modify 
Syntax 
W 
Description 
This command displays and/or modifies the contents of W register. 
 
Examples: 
MPSIM Command     Result 
% W               W=44: 
                  The value of W is 44 as the following message shows. 
                  W=44:00 
                  Change the value by entering a different value after the ':'  
                   prompt. 
                  The W register now has a value of 0. 
Defaults 
None. 
 
Related Commands 
None. 
 
 
WP   -  Watchdog Timer Period 
Syntax: 
  WP {1 | . . . | 128} 
 
Description: 
  Sets watchdog timer time-out period.  With no parameters, displays current  
setting. 
 
Examples: 
MPSIM Command     Result 
% WP              Display current period 
% WP 10           WDT period set to 10 ms. 
 
Defaults 
Normal period for selected Microcontroller. 
 
Related Commands 
None 
 
 
ZM   -  Zero the Program Memory 
Syntax 
  ZM address1,address2 
 
Description: 
  This command zeros the program memory from address1 to address2.  address1  
must less than address2 and both must be valid program memory addresses. 
 
Examples: 
MPSIM Command     Result 
% ZM 0, 1F        Program memory from 0 to 1F is zeroed. 
 
Defaults 
None. 
 
Related Commands 
None. 
 
 
ZP   -  Zero the Patch Table 
Syntax 
  ZP 
 
Description 
This command clears the patch table.  Clears the patch table and resets it to  
no patches made.  Any changes made to the object code are unaffected.  Thus,  
the object code cannot be restored to the original. 
 
Examples: 
MPSIM Command      Result 
% ZP               Patch table cleared. 
 
Defaults 
None. 
 
Related Commands 
O, RA, RP 
 
 
ZR   -  Zero the Registers 
Syntax 
  ZR 
 
Description: 
  This command sets all of the file registers to zero.  Care should be taken  
with this instruction since it will zero the lower 8 bits of F2 (PC).  An RS  
command should follow the ZR command to ensure the PC is set the expected  
reset value. 
 
Examples: 
MPSIM Command        Result 
% ZR                 All registers are zeroed.  
 
Defaults 
None. 
 
Related Commands 
DR, RS, SE 
 
 
ZT   -  Zero the Elapsed Time Counter 
Syntax: 
  ZT 
 
Description: 
  This command zeros the elapsed time counter. 
 
Examples: 
MPSIM Command     Result 
% ZT              The elapsed time counter resets to zero. 
 
Defaults 
None. 
 
Related Commands 
RE, RS 
 
 
Appendix A.   Troubleshooting Guide 
 
Introduction 
This Appendix consists of the following sections: 
   -  Solutions to common problems 
   -  The three types of messages generated by MPSIM, grouped by severity and  
their possible causes and solutions. Messages have been divided into the  
following groups: 
   -  Informative Messages 
   -  Warning Messages 
   -  Error Messages 
 
Solutions to Some Common Problems 
Problem 1: 
I keep getting strange error messages like stack underflow or Illegal Opcode  
when single-stepping through or executing my code. 
Solution 1: 
Check to make sure that the processor type you selected in MPSIM is the same  
as the processor type you selected when you assembled your code. This is  
especially important when simulating the members of the PIC16CXX or  P{IC17CXX  
family since the object code for them is different from the PIC16C5X, and the  
default processor type for the simulator is the PIC16C54. 
 
Problem 2: 
When I am trying to step through my code, MPSIM seems to execute an  
instruction different from the one that is displayed in the command area. 
Solution 2: 
Check to make sure that you loaded your code into the simulator in the same  
format that assembled it. For example, if you assembled your code and didn't  
specify an output format, your hex file will be in INHX8M format. If you then  
load your code into the simulator in INHX8S format, the simulator will behave  
strangely.  
 
Problem 3: 
MPSIM does not perform indirect addressing correctly. 
Solution 3: 
Check to make sure that you do not have your indirect addr register defined as  
the label F0 in your source file. There is a symbol-table conflict when you  
define your label as such. Rename the F0 label in your source file to IND0 or  
any other label. 
 
Problem 4: 
The W register does not update on my screen. 
Solution 4: 
You have redefined W in your source file to be equal to zero, and MPSIM now  
treats W as file register 0. Change the label in your source file to Wreg or  
something similar. 
 
 
Messages 
 
Informative Messages 
Address Break After 
Cause: The breakpoint mode has been set to break after the instruction  
has been executed. 
 
Break at Address 
Cause: A breakpoint has been encountered and execution has stopped. 
 
Break at Register 
Cause: A break on register condition has been encountered and execution  
has stopped. 
 
Interrupt at Address 
Cause: Execution has stopped at the indicated address due to a user  
keyboard interrupt. 
 
Listing File Loaded 
Cause: MPSIM found and read filename.LST 
 
No Symbols Defined! 
Cause: The user has requested a list of all symbols when no symbols had  
been defined. 
 
Object Code Written to Disk 
Cause: MPSIM successfully dumped program memory to the named object file. 
 
Original Source Restored 
Cause: MPSIM has restored the source to its original form upon user  
request. 
 
Out of Memory, Not all Source Lines Loaded 
Cause: MPSIM has exhausted free memory while trying to load the listing  
file. 
 
Processor Reset 
Cause: MPSIM has reset the processor due to a user request. 
 
Symbol Table Loaded 
Cause: MPSIM has found and read filename.SYM. 
 
Trace File is Closed 
Cause: MPSIM has successfully closed the trace file. 
 
Trace File is Open 
Cause: MPSIM has successfully opened the trace file. 
 
Verbose is OFF 
Cause: Verbose mode is currently OFF, extended user messages will not be  
displayed. 
 
Verbose is ON 
Cause: Verbose mode is currently ON, extended user messages will be  
displayed. 
 
Watch Dog Timer Disabled 
Cause: MPSIM will not respond to watchdog timer time-outs. 
 
Watch Dog Timer Enabled 
Cause: MPSIM will respond to watchdog timer time-outs. 
 
Warning Messages 
Address2 < Address1 
Cause: When entering a starting and ending address for a command, the  
ending address is greater than the ending address. 
Cure: The starting address must be less than or equal to the ending address. 
 
Arg X out of Range LABEL 
Cause: You have entered a operand that is out of range of the specified  
instruction 
Cure: Review the instruction syntax and re-enter. 
 
Attempt to Read Nonexistent File Register 
Cause: Your object code has attempted to read a file register that does  
not exist in the PIC16/17 Microcontroller you have specified. 
Cure: Set you PIC16/17 Microcontroller type accordingly. 
 
Attempt to Write Nonexistent File Register 
Cause: Your object code has attempted to read a file register that does  
not exist in the PIC16/17 Microcontroller you have specified. 
Cure: Set your PIC16/17 Microcontroller type accordingly. 
 
Bad Break Value 
Cause: While defining a register breakpoint, you have specified a break  
value that is either unrecognized in the default radix or is out of range for  
the file register. 
Cure: Ensure the value is valid in the current radix and not out of range of  
the file register. 
 
Bad Count 
Cause: You have entered a break count that is unrecognized in the current  
radix. 
Cure: Ensure that the value is correct in the current radix. 
 
Bad Cycle Length 
Cause: You have entered a cycle length that is invalid or unrecognizable. 
Cure: Re-enter the cycle length. 
 
Bad End Address 
Cause: You have entered an ending address that is out of memory bounds or  
unrecognizable in the current radix. 
Cure: Ensure that the value is valid in the current radix and re-enter. 
 
Bad Filename 
Cause: The file name you entered was not recognizable as a DOS file name. 
Cure: Ensure the file name conforms to DOS naming standards. 
 
Bad Max. Value 
Cause: This maximum value you entered is not recognizable in the current  
radix. 
Cure: Ensure the value is valid in the current radix and re-enter. 
 
Bad Min. Value 
Cause: This minimum value you entered is not recognizable in the current  
radix. 
Cure: Ensure the value is valid in the current radix and re-enter. 
 
Bad Opcode 
Cause: While attempting to search program memory for a specified opcode,  
the opcode you entered is unrecognizable in the current radix. 
Cure: Ensure the opcode is valid in the current radix and re-enter. 
 
Bad Option 
Cause: The option you supplied to the V command was not valid. 
Cure: Valid options are on and off. Use on of the valid options. 
 
Bad Signal Value 
Cause: While attempting to modify an I/O pin's value, you have entered a  
value that is unrecognizable in the current radix. 
Cure: re-enter the value ensuring it is valid in the current radix. 
 
Bad Value 
Cause: You have entered a value that is out of range of the file register  
or unrecognized in the current radix. 
Cure: Ensure the value is valid in the current radix and in range for the file  
register. 
 
Bad Width 
Cause: The number you specified as the width of a view screen element was  
not recognized 
Cure: Ensure the width is a valid number in the current radix. 
 
Can only Break on File Registers or Addresses 
Cause: You have attempted to set a break point on an I/O pin 
Cure: Break points on I/O pins are disallowed. 
 
Cannot Add Symbol to Symbol Table 
Cause: Due to memory constraints, MPSIM cannot add the specified symbol  
to the symbol table. 
Cure: Increase the amount of free memory before entering MPSIM. 
 
Cannot Find Command File 
Cause: MPSIM cannot find the command file you specified. 
Cure: Ensure that the file is present in the path that you specified in the  
command. 
 
Cannot Find Command File (MPSIM.jrn) 
Cause: MPSIM cannot find the old journal file. 
Cure: If MPSIM.jrn was not present in the current directory, this message is  
informational only. If the file is present, this may signal more serious  
errors with your disk. 
 
Cannot Find List File 
Cause: MPSIM cannot find the list file with the same name as the hex file  
plus the .LST extension. 
Cure: Ensure you have a list file in the same directory as the hex file you  
specified. 
 
Cannot Find Symbol File 
Cause: MPSIM cannot find the symbol file with the same name as the hex  
file plus the .SYM extension. 
Cure: Ensure you have a symbol file in the same directory as the hex file you  
specified. 
 
Cannot Open Trace File 
Cause: MPSIM cannot open the file you specified. This may be caused by  
any number of DOS errors. 
Cure: Ensure that the file you specified doesn't exist and is read-only, or  
you have exhausted the number of DOS file handles. 
 
Cannot Parse Filename 
Cause: The file name you entered was not recognizable as a DOS file name. 
Cure: Ensure the file name conforms to DOS naming standards. 
 
Cannot Search for an IO Pin or Status Bit 
Cause: You have attempted to search program memory for an instruction  
modifying an I/O pin or a status bit. 
Cure: This operation is not supported. 
 
Cannot Trace an IO Pin or Status Bit 
Cause: You have attempted to set a trace on an I/O pin or Status Bit 
Cure: This operation is not supported. 
 
File Symbol does not Match Page at PC=XXX 
Cause: MPSIM has detected a page mismatch between the file symbol and the  
page select bits in the FSR. 
Cure: This is a software error, your code needs to be fixed. 
 
Invalid Filename 
Cause: The file name you entered was not recognizable as a DOS file name. 
Cure: Ensure the file name conforms to DOS naming standards. 
 
Illegal Number of Arguments 
Cause: You have entered the wrong number of arguments for the command 
Cure: Supply all required arguments for the command. 
 
Illegal Radix 
Cause: You have given a radix modifier that is not recognized. 
Cure: Valid radix modifiers are X, D, O and B. Use one of the valid types. 
 
Missing Instruction 
Cause: You have told MPSIM to assemble an instruction, but did not supply  
the instruction 
Cure: Re-enter the command with the desired instruction. 
 
No Breaks Found Involving 
Cause: While trying to delete a register breakpoint, you have specified a  
file register that has no associated break point. 
Cure: Ensure that a breakpoint for the specified file register has been  
defined via the DB command. 
 
No Object Code Loaded 
Cause: MPSIM cannot open the object file and as a result cannot load the  
object code. 
Cure: Ensure that the file name you specified is present in the directory you  
specified. 
 
Opcode can only be used in PIC16C55/57 Mode 
Cause: MPSIM has tried to execute an instruction that is valid only for  
the PIC16C55 or PIC16C57. Most likely a TRIS 7 instruction. 
Cure: Your Microcontroller type is not set properly. Refer to the P command. 
 
Out of Memory 
Cause: While defining a register breakpoint, MPSIM has exhausted free  
memory. 
Cure: Increase the amount of free memory before entering MPSIM or rename the  
list file so that MPSIM cannot find it. 
 
Stack Overflow 
Cause: You have executed one too many RETLW instructions for the contents  
of the Microcontroller stack. 
Cure: This is a software error, your code needs to be fixed. 
 
Stack Underflow 
Cause: You have executed one too many CALL instructions for the size of  
the Microcontroller stack. 
Cure: This is a software error, your code needs to be fixed. 
 
Start Address Exceeds End Address 
Cause: When entering a starting and ending address for a command, the  
ending address is greater than the ending address. 
Cure: The starting address must be less than or equal to the ending address. 
 
Symbol Already Exists 
Cause: You have attempted to define a symbol that already exists. 
Cure: Use a different symbol name. 
 
Too Many Arguments 
Cause: You have entered too many arguments for the command. 
Cure: Review the common syntax. 
 
Unable to Open Object File 
Cause: MPSIM cannot open the object file specified. 
Cure: Ensure that the file is present in the directory you specified. 
 
Undefined Symbol 
Cause: You have attempted to delete a nonexistent symbol 
Cure: Ensure that the symbol is defined. Symbols are case sensitive. If you  
used the case insensitivity switch in the assembler, all symbols have been  
mapped to uppercase. 
 
Uninitialized Memory Location Executed 
Cause: MPSIM has attempted to execute a memory location that does not  
have any object code loaded. 
Cure: Ensure that there is object code loaded and your program is not running  
amuck. 
 
Unknown Break Mode 
Cause: You have specified a break mode that is unrecognized to MPSIM. 
Cure: Valid break modes are before and after. Use one of the valid break  
modes. 
 
Unknown File Format 
Cause: MPSIM has tried to read in an object file that is does not  
recognize. 
Cure: Ensure that the file you specified is a valid object file in the format  
you specified. 
 
Unknown Instruction XXX 
Cause: You have told MPSIM to assemble an instruction which is not a  
valid PIC16C5X instruction. 
Cure: re-enter the instruction in valid PIC16C5X mnemonics. 
 
Unknown Opcode XXX 
Cause: There is an invalid opcode in your object file.  
Cure: Ensure that you have loaded your object file in the correct format.  
Default is INHX16. 
 
Unknown Operator 
Cause: While defining a register breakpoint, you have used an  
unrecognized logical operator. 
Cure: Valid operators are <, >, <=, >=, =, !=. Use one of the valid operators. 
 
Unknown Radix 
Cause: You have attempted to modify the default radix to a value that is  
unrecognized by MPSIM. 
Cure: Valid radix values are X, D and O. Use one of the valid values. 
 
Unknown Symbol Type 
Cause: While attempting to define a new symbol, you have entered a symbol  
type that is unrecognized by MPSIM. 
Cure: Valid symbol types are F, L, K and B. Use one of the valid symbol types. 
 
Use SE Command to Modify IO Pins 
Cause: You have attempted to use the F command to modify an I/O pin 
Cure: Use the SE command. 
 
Value Out of Range 
Cause: You have specified a value that is out of range or unrecognized in  
the current radix. 
Cure: Ensure that the value is valid in the current radix and valid for the  
current operation. 
 
View Item not Found 
Cause: You have attempted to delete or modify a nonexistent view screen  
element 
Cure: Ensure that the element is present on the view screen. View screen  
elements are case-sensitive. 
 
ViewScreen is Full 
Cause: You have attempted to add an element to the view screen when there  
is no more room on the screen. 
Cure: Since the view screen is static in this version, there is no work- 
around. 
 
WDT Time-out 
Cause: The watchdog timer has timed out. 
Cure: Ensure the settings for the WDT are correct and your software resets the  
WDT appropriately. 
 
XXX is not an IO Pin 
Cause: You have tried to use the SE command to modify a label that is not  
an I/O pin. 
Cure: Use the F command to modify file registers, status bits and the  
 stack. 
Error Messages 
 
Bad Stimulus (Line X) 
Cause: MPSIM has found a stimulus value other that zero or one. 
Cure: All pin stimuli must be either zero or one. 
 
Cannot Delete Old Journal File 
Cause: The file MPSIM.JRN has been read protected. 
Cure: If you intended for the file to be read protected then do not worry  
about this error otherwise read enable the file. 
 
Cannot Find Heading Line in Stimulus File 
Cause: MPSIM cannot find the heading line in the stimulus file. 
Cure: Ensure that there is a line in the file which begins with STEP. 
 
Cannot Map Stimulus, Symbol Conflict XXX 
Cause: MPSIM has encountered two column headings that are identical. 
Cure: Ensure your column headings are correct. 
 
Cannot Open File for Input XXX 
Cause: MPSIM cannot open the specified file for reading. 
Cure: Either the file does not exist or the file is read-only. 
 
Cannot Open Journal File 
Cause: MPSIM cannot open the old journal file. 
Cure: The file MPSIM.JRN has been read protected, change the DOS attribute. 
 
Cannot Update Journal File 
Cause: MPSIM cannot update the journal file with the new commands for  
this session. 
Cure: Either the old MPSIM.JRN cannot be deleted or the new journal file does  
not exist. Contact your local FAE. 
 
Duplicate Symbol in Symbol File 
Cause: MPSIM has encountered a symbol in the symbol file that has already  
been defined. 
Cure: Delete the duplicate reference. If MPSIM finds this error it will not  
continue to read the symbol file. 
 
First Heading in Stimulus File MUST be STEP 
Cause: The line that MPSIM interpreted as the heading line did not begin  
with STEP. 
Cure: Make sure all comment lines begin with !' and the heading line begins  
with STEP. 
 
Out of Memory, Cannot Create Event Calendar 
Cause: MPSIM exhausted free memory while trying to create the event  
calendar. 
Cure: Increase the amount of free memory before invoking MPSIM. 
 
Out of Memory, Cannot Create Event (Line X) 
Cause: MPSIM exhausted free memory while trying to create an event. 
Cure: Increase the amount of free memory before invoking MPSIM. 
 
Out of Memory During Build of Break 
Cause: MPSIM exhausted free memory while trying to define a file register  
breakpoint. 
Cure: Increase the amount of free memory before invoking MPSIM. 
 
Stimulus Data does not Match Headings (Line X) 
Cause: MPSIM has found a line that has too few or too many data points to  
match the column headings. 
Cure: Ensure each data line has one data point for each column heading. 
 
Symbol File does not Match Hex File 
Cause: You have tried to load a symbol file that was not generated for  
the current hex file. 
Cure: If you intended to load the symbol file, the embedded file name must  
match the file name of the symbol file. 
 
Symbol File is Corrupt 
Cause: MPSIM has encountered some unexpected formatting in the symbol  
file. 
Cure: Regenerate the symbol file. 
 
Symbol File Sync Error 
Cause: MPSIM has gotten lost while trying to parse the symbol file. Most  
likely the symbol file is corrupt. 
Cure: Regenerate the symbol file. 
 
Too Many Headings in Stimulus File (MAX=40) 
Cause: The stimulus file has a limit of 40 headings, enough for each I/O  
pin. 
Cure: If there is a need for more headings, contact your local FAE. 
 
Unknown Command 
Cause: MPSIM does not recognize the command you entered. 
Cure: Refer to the command summary for valid commands. 
 
Unexpected EOF in Stimulus File 
Cause: While reading the stimulus file, MPSIM encountered a line that did  
not have the proper number of data points. 
Cure: Ensure that all data lines have the correct number of data points 
 
Unknown File Register X 
Cause: MPSIM does not recognize the file register as an argument to the  
instruction. 
Cure: Re-enter the mnemonic with a valid file register. 
 
Unknown Option X 
Cause: MPSIM does not recognize the command line option X. 
Cure: Refer to the section on command line arguments. 
 
Unknown Opcode (X) 
 
Cause: MPSIM tried to execute an opcode that is not a valid PIC16C5X  
opcode. 
Cure: Ensure you loaded the object file in the correct format. INHX16 and  
INHX8M have different byte orders. 
 
 
 
Customer Support 
 
Keeping Current with Microchip Systems 
 
This chapter provides a brief discussion of the Microchip BBS general services available.  
Because the Microchip BBS is an evolving product, details of its operation are not  
described here. This chapter also describes the Microchip software release numbering  
scheme. 
 
Microchip Technology supports the Microchip BBS as a service to its customers. The  
Microchip BBS contains the most recent information regarding Microchip systems products.  
microchip endeavors at all times to provide quality service and fast responsiveness to  
users. to accomplish this, Microchip monitors the BBS several times a week for questions.  
Truly urgent issues should not be left with the BBS, but referred to your local  
distributor, sales office or FAE. 
 
Note: the best way to keep current with Microchip systems is to register. 
 
Highlights 
The highlighted points in this chapter include: 
 - Keeping Current with Microchip Systems 
 - Systems Information and Upgrade Hot Line 
 - Connecting to Microchip BBS 
 - Using the Bulletin Board 
 - Special Interest Groups 
 - Files 
 - Mail 
 - Software Releases 
 - Alpha Release 
 - Intermediate Release 
 - Beta Release 
 - Production Release 
 
Systems Information and Upgrade Hot Line 
The Systems Information And Upgrade Line provides system users a  
listing of the latest versions of all of Microchip's development systems software  
products. Plus, this line provides information on how customers  
can receive any currently available upgrade kits. The Hot Line Numbers  
are: 1-800-755-2345 for U.S. and most of Canada, and 1-602-786-7302  
for the rest of the world. 
 
These phone numbers are also listed on the Important Information sheet that is shipped  
with all development systems. The hot line message is updated whenever a new software  
version is added to the Microchip BBS, or when a new upgrade kit becomes available. 
 
Connecting to Microchip BBS 
Connect worldwide to the Microchip BBS using the CompuServe communications network. In  
most cases, a local call is your only expense.  
 
The Microchip BBS connection does not use CompuServe membership services, therefore, you  
do not need CompuServe membership to join Microchips BBS. 
 
There is no charge for connecting to the BBS. There is no charge to dial the CompuServe  
access number. You do not need to be a CompuServe member to take advantage of this  
connection (you never actually log in to CompuServe). 
 
The procedure to connect will vary slightly from country to country. Please check with  
your local CompuServe agent for details if you have a problem. CompuServe services allow  
multiple users at baud rates up to 14.4 kbps. 
 
The following connect procedure applies in most locations. 
1. Set your modem to 8-bit, No parity, and One stop (8N1). this is not the normal  
       CompuServe setting which is 7E1. 
2. Dial your local CompuServe access number. 
3. Depress <Enter> and a garbage string will appear because CompuServe is expecting  
       a 7E1 setting. 
4. Type +, depress <Enter> and Host Name: will appear. 
5. Type MCHIPBBS, depress <Enter> and you will be connected to the Microchip  
       BBS. 
6. In the United States, to find CompuServes phone number closest to you, set your  
       modem to 7E1 and dial (800) 848-4480 for 300-2400 baud or (800) 331-7166 for  
       9600- 14400 baud connection.  
 
After the system responds with  
    Host Name: 
type NETWORK, depress <Enter> and follow CompuServe's directions. 
 
For  voice information (or calling from overseas), you may call (614) 457-1550 for your  
local CompuServe number. 
 
Using the Bulletin Board 
The bulletin board is a multifaceted tool. It can provide you with information on a number  
of different topics. 
 - Special Interest Groups 
 - Files 
 - Mail 
 - Bug Lists 
Special Interest Groups 
Special Interest Groups, or SIGs as they are commonly referred to, provide you with the  
opportunity to discuss issues and topics of interest with others that share your interest  
or questions. SIGs may provide you with information not available by any other method  
because of the broad background of the PIC16/17 user community. 
There are SIGs for most Microchip systems, including: 
 
MPASM 
 
MPSIM 
 
PICMASTER 
 
TRUE GAUGE 
 
PRO MATE 
 
fuzzyTECH-MP 
 
Utilities 
 
ASSP 
 
Bugs 
 
 
These groups are monitored by the Microchip staff. 
 
Files 
Microchip regularly issues the Microchip BBS to distribute technical information,  
Application Notes source code, errata sheets, bug reports, and interim patches for  
Microchip systems software products. Users can contribute files for distribution on the  
BBS. For each SIG, a moderator monitors, scans, and approves or disapproves files  
submitted to the SIG. No executable files are accepted from the user community in general  
to limit the spread of computer viruses. 
 
Mail 
The BBS can be used to distribute mail to other users of the service. This is one way to  
get answers to your questions and problems from the Microchip staff, as well as keeping in  
touch with fellow Microchip users worldwide. 
 
Consider mailing the moderator of your SIG, or the SYSOP, if you have ideas or questions  
about Microchip products, or the operation of the BBS.  
 
Note: The SIGs provide you with the opportunity to discuss issues and exchange ideas.  
 
Technical support and urgent questions should be referred to your local distributor, sales  
representative or FAE. They are your first level of support. 
 
Software Releases 
Software products released by Microchip are referred to by version numbers. Version  
numbers use the form: 
    xx.yy.zz <status> 
Where xx is the major release number, yy is the minor number, and ZZ is the intermediate  
number. The status field displays one of the following categories: 
 - Alpha 
 - Intermediate 
 - Beta 
 - Released 
 
Production releases are numbered with major, and minor version numbers like: 
3.04 Released 
 
Alpha, Beta and Intermediate releases are numbered with the major, minor and intermediate  
numbers: 
3.04.01 Alpha 
 
Alpha Release 
Alpha designated software is engineering software that has not been submitted to any  
quality assurance testing. In general, this grade of software is intended for software  
development team access only, but may be sent to selected individuals for conceptual  
evaluation. Once Alpha grade software has passed quality assurance testing, it may be  
upgraded to Beta or Intermediate status. 
 
Intermediate Release 
Intermediate released software represents changes to a released software system and is  
designated as such by adding an intermediate number to the version number. Intermediate  
changes are represented by: 
 - Bug Fixes 
 - Special Releases 
 - Feature Experiments 
 
Intermediate released software does not represent our most tested and stable software.  
Typically, it will not have been subject to a thorough and rigorous test suite, unlike  
production released versions. Therefore, users should use these versions with care, and  
only in cases where the features provided by an intermediate release are required. 
Intermediate releases are primarily available through the BBS. 
 
Beta Release 
Preproduction software is designated as Beta. Beta software is sent to  
Applications Engineers and Consultants, FAEs, and select customers. The Beta Test period  
is limited to a few weeks. Software that passes Beta testing without having significant  
flaws, will be production released. Flawed software will be evaluated, repaired, and  
updated with a new revision number for a subsequent Beta trial. 
 
Production Release 
Production released software is software shipped with tool products. Example products are  
PRO MATE, PICSTART, and PICMASTER. The Major number is advanced when significant feature  
enhancements are made to the product. The minor version number is advanced for maintenance  
fixes and minor enhancements. Production released software represents Microchip's most  
stable and thoroughly tested software. 
 
There will always be a period of time when the Production Released software is not  
reflected by products being shipped until stocks are rotated. You should always check the  
BBS for the current production release. 
 
 
 
 
 
PIC16C5X User's Guide Addendum 
 
Introduction 
MPSIM provides support for more than one family of Microchip microcontrollers.   
This section has been added as an addendum to the MPSIM users guide to  
centralize PIC16C5X-specific simulator support.    
 
I/O Pins 
The PIC16C5X family consists of the PIC16C54, PIC16C55, PIC16C56, PIC16C57,  
and PIC16C58A. When modifying pins either manually (with the SE command) or  
via the stimulus file, use the following pin names only. These are the only  
ones that MPSIM recognizes as valid I/O pins. Because the pinout is device- 
specific, some pins (for example RC0 on a PIC16C54) will not be available on  
all parts in this family. 
  -  MCLR 
  -  RTCC 
  -  RA0-RA3 
  -  RB0-RB7 
  -  RC0-RC7 
 
CPU Model 
 
Reset Conditions 
All reset conditions are supported by MPSIM.   
A Power-On-Reset can be simulated by using the RS instruction.  All special- 
purpose registers will be initialized to the values specified in the data  
sheet. 
 
A MCLR reset during normal operation or during SLEEP can easily be simulated  
by driving the MCLR pin low (and then high) via the stimulus file or by using  
the SE command or by using DK command.   
 
A WDT time-out reset is simulated when WDT is enabled (see DW command) and  
proper prescaler is set (by initializing OPTION register appropriately) and  
WDT actually overflows. WDT time-out period (with prescale = 1) is  
approximated at 18 ms (to closest instruction cycle multiple).  
 
The Time-out (TO) and Power-down (PD) bits in the Status register reflect  
appropriate reset condition.  This feature is useful for simulating various  
power-up and time out forks in the user code. 
Sleep 
 
MPSIM simulates the SLEEP instruction, and will appear 'asleep' until a wake- 
up from sleep condition occurs.  For example, if the Watchdog timer has been  
enabled, it will wake the processor up from sleep when it times out (depending  
upon the prescaler setting in the OPTION register).  
WDT 
 
The Watchdog timer is fully simulated in the MPSIM simulator.  Because it is  
fuse-selectable on the device, it must be enabled by a separate command (see  
the DW command) in MPSIM.  The period of the WDT is determined by the  
prescaler settings in the OPTION register. The basic period (with prescaler =  
1) is approximated at 18 ms (to closest instruction cycle multiple). 
Stack 
 
MPSIM presents an accurate simulation of the hardware stack on the PIC16C5X,  
and additionally provides warning messages if an underflow or overflow  
condition occurs.  When a CALL instruction is encountered, or when an  
interrupt has occurred, the value of the PC+ 1 is pushed to the stack, and the  
stack is popped when a RETLW, RETURN, or RETFIE instruction is executed.  If  
more than two values are pushed to the stack before it is popped, the value  
will be pushed to the stack, but a warning message will be issued, indicating  
a stack overflow condition.  An error message will also be generated if the  
user attempts to pop an empty stack.  Popping an empty stack will cause the  
last value popped to be put in the PC. 
 
Special Registers 
To aid in debugging this device, certain items that are normally not  
observable have been declared as 'special' registers. For example, the W  
register is not directly-addressable, but can be added to the viewscreen, by  
adding the special label 'W' or 'w' with the AD command, just as any register.  
The following is a complete list of 'special' registers that can be added to  
the viewscreen and observed or modified. You can add them as you normally  
would any other register declared in your code, specifying any radix to view  
them. 
  -  W (or w) 
  -  TRISA 
  -  TRISB 
  -  TRISC 
  -  OPT (the option register)  
 
It is important not to redefine these special labels. For example, do not  
define the label 'W' to be equal to zero in your source code. This will cause  
the special label to be overridden, and 'W' will now be the indirect-address  
register (IND0).  
 
Peripherals 
 
Peripherals Supported 
Along with providing core support, the RTCC timer/counter module is fully  
supported. It is fully supported in internal and external clock modes. The  
prescaler is made readable and writable as 'RTCCPRE'' symbol. 
 
It is important to remember that because MPSIM executes on instruction cycle  
boundaries, resolutions below 1 Tcy cannot be simulated.   
 
MPSIM is a discrete-event simulator where all stimuli are evaluated and all  
response generated at instruction boundaries or Tcy.  One Tcy = 4 Tosc (where  
Tosc is input clock).  Therefore, there are several events that can not be  
accurately simulated in MPSIM.  These fall into two categories: 
  -  Purely asynchronous events 
  -  Synchronous events that occur at Tosc clock boundaries 
Because of this, the following items are not supported in MPSIM: 
  -  Timer0 prescaler is capable of accepting clock pulse inputs smaller than   
Tcy, but this can not be simulated. 
 
In summary, the net result of instruction boundary simulation is that all  
events get synchronized at instruction boundary and events smaller than one  
instruction cycle get lost. 
 
 
 
PIC16C64 User's Guide Addendum 
 
Introduction 
MPSIM provides support for more than one family of Microchip microcontrollers.   
This section has been added as an addendum to the MPSIM user's guide to  
centralize PIC16C64-specific simulator support.    
 
I/O Pins 
The PIC16C64 is a 40-pin device, with many of the I/O pins multiplexed with  
other peripherals (and therefore referred by more than one name).  When  
modifying pins either manually (e.g. with the SE command) or via the stimulus  
file,  use the following pin names only.  These are the only ones that MPSIM  
recognizes as valid I/O pins: 
   -    MCLR 
   -    RA0-RA5 
   -    RB0-RB7 
   -    RC0-RC7 
   -    RD0-RD7 
   -    RE0-RE2 
 
Interrupts 
MPSIM version 4.5 or greater supports all interrupts on the PIC16C64: 
   -    Timer0 overflow 
   -    Timer1 overflow 
   -    Timer2  
   -    CCP1 
   -    SSP (in SPI mode ONLY) 
   -    Change on Port RB <7..4> 
   -    External interrupt from RB0/INT pin 
   -    Parallel Slave Port 
 
CPU Model 
 
Reset Conditions 
All reset conditions are supported by MPSIM.   
A Power-On-Reset can be simulated by using the RS instruction.  All special- 
purpose registers will be initialized to the values specified in the data  
sheet. 
 
A MCLR reset during normal operation or during SLEEP can easily be simulated  
by driving the MCLR pin low (and then high) via the stimulus file or by using  
the SE command or by using DK command.   
 
A WDT time-out reset is simulated when WDT is enabled (see DW command) and  
proper prescaler is set (by initializing OPTION register appropriately) and  
WDT actually overflows. WDT time-out period (with prescale = 1) is  
approximated at 18 ms (to closest instruction cycle multiple).  
 
The Time-out (TO) and Power-down (PD) bits in the Status register reflect  
appropriate reset condition.  This feature is useful for simulating various  
power-up and time out forks in the user code. 
 
Sleep 
MPSIM simulates the SLEEP instruction, and will appear asleep until a wake-up  
from sleep condition occurs.  For example, if the Watchdog timer has been  
enabled, it will wake the processor up from sleep when it times out (depending  
upon the prescaler setting in the OPTION register).  Another example of a  
wake-up-from-sleep condition, would be Timer1 wake-up from sleep.  In this  
case, when the processor is asleep, Timer1 would continue to increment until  
it overflows, and if the interrupt is enabled, will wake the processor on  
overflow and branch to the interrupt vector. 
 
WDT 
The Watchdog timer is fully simulated in the MPSIM simulator.  Because it is  
fuse-selectable on the device, it must be enabled by a separate command (see  
the DW command) in MPSIM.  The period of the WDT is determined by the  
prescaler settings in the OPTION register. The basic period (with prescaler =  
1) is approximated at 18 ms (to closest instruction cycle multiple). 
 
Stack 
MPSIM presents an accurate simulation of the hardware stack on the PIC16CXX,  
and additionally provides warning messages if an underflow or overflow  
condition occurs.  When a CALL instruction is encountered, or when an  
interrupt has occurred, the value of the PC+ 1 is pushed to the stack, and the  
stack is popped when a RETLW, RETURN, or RETFIE instruction is executed.  If  
more than eight values are pushed to the stack before it is popped, the value  
will be pushed to the stack, but a warning message will be issued, indicating  
a stack overflow condition.  An error message will also be generated if the  
user attempts to pop an empty stack.  Popping an empty stack will cause the  
stack pointer to point to the top of a full stack, and will not generate an  
error message if another pop is initiated. 
 
Special Registers 
To aid in debugging this device, certain items that are normally not  
observable have been declared as special registers.    Prescalers and  
postscalers cannot be declared in your code as registers, so there are special  
labels that can be added to the view screen.  You can add them as you normally  
would any other register declared in your code,  specifying any radix to view  
them. 
 
The following are special items that can be added to the view screen when the  
PIC16C64 has been selected: 
   -    T0PRE - Prescaler for timer0 
   -    T1PRE - Prescaler for timer1 
   -    T2PRE - Prescaler for timer2 
   -    T2POS - Postscaler for timer2 
   -    CCP1PRE - Prescaler for CCP1 
   -    SPIPRE - Prescaler for SPI 
   -    SSPSR - SSP Shift register 
Please remember that these labels are only available when the PIC16C64 is the  
target processor, and that they cannot be manually modified. 
 
 
Peripherals 
 
Peripherals Supported 
Along with providing core support, the following peripheral modules (in  
addition to general-purpose I/O) are supported: 
   -    Timer0 
   -    Timer1 
   -    Timer2 
   -    CCP1 
   -    Parallel Slave Port 
   -    SSP (in SPI Mode only) 
 
Tcycle Limitation 
It is important to remember that because MPSIM executes on instruction cycle  
boundaries, resolutions below 1 Tcy cannot be simulated.  Please see the  
following section for more details concerning the limitations of T-cycle  
simulation. 
 
MPSIM is a discrete-event simulator where all stimuli are evaluated and all  
response generated at instruction boundaries or Tcy.  One Tcy = 4 Tosc (where  
Tosc is input clock).  Therefore, there are several events that can not be  
accurately simulated in MPSIM.  These fall into two categories: 
   -  Purely asynchronous events 
   -  Synchronous events that occur at Tosc clock boundaries 
Because of this, the following items are not supported in MPSIM: 
   -  Timer0, Timer1, and Timer2 prescalers are capable of accepting clock  
pulse inputs smaller than Tcy, but these can not be simulated. 
   -  Capture input pulses can be smaller than one Tcy, but can not be  
simulated. 
   -  PWM output pulse resolution less than 1 Tcy is not supported. 
   -  8-bit compare will not be supported since the output resolution is  
limited to T cycles 
   -  In unsynchronized counter mode, clock input smaller than Tcy is not  
supported 
   -  The oscillator on RC0/RC1 pins is not supported.  The user can, however,  
simply use an external clock input for simulation purposes. 
In summary, the net result of instruction boundary simulation is that all  
events get synchronized at instruction boundary and events smaller than one  
instruction cycle get lost. 
 
TIMER0 
Timer0 (and the interrupt it can generate on overflow) is fully supported by  
MPSIM, and will increment by the internal or external clock.  Clock input must  
have a minimum high time of 1Tcy and a minimum low time of 1Tcy due to  
stimulus file requirements.  The prescaler for Timer0 is made accessible as  
T0PRE. It can be watched and modified. 
 
TIMER1 
Timer1 in its various modes is supported by MPSIM, except when running in  
counter mode by an external crystal.  The interrupt it can be generated on  
overflow and wake-up from sleep through interrupt are both supported by MPSIM.   
The prescaler for Timer1 is viewable and modifiable as T1PRE. The external  
oscillator on RC0/RC1 is not  simulated. The user can simply use a clock input  
(see CK command). 
 
TIMER2  
Timer2 and the interrupt that can be generated on overflow are fully supported  
by MPSIM, and both the prescaler and postscaler for Timer2 are viewable and  
modifiable (T2PRE and T2POS).  
 
CCP1 
 
CAPTURE 
MPSIM fully supports capture and the interrupt generated.  The prescaler for  
the CCP module is viewable and modifiable (CCP1PRE). 
 
COMPARE  
Compare mode, its interrupt, and the special event trigger (resetting Timer1  
by CCP1) are supported in this version of MPSIM. 
 
PWM 
PWM output (resolution greater than 1Tcy only) are supported in this version  
of MPSIM. 
 
SSP 
The Synchronous Serial Port is supported in SPI mode only.  The shift register  
(SSPSR) can be added to the viewscreen, observed and modified.  MPSIM  
currently does not support the I2C mode. 
 
 
PIC16C65 User's Guide Addendum 
 
Introduction 
MPSIM provides support for more than one family of Microchip microcontrollers.   
This section has been added as an addendum to the MPSIM user's guide to  
centralize PIC16C65-specific simulator support.    
 
I/O Pins 
The PIC16C65 is a 40-pin device, with many of the I/O pins multiplexed with  
other peripherals (and therefore referred by more than one name).  When  
modifying pins either manually (e.g. with the SE command) or via the stimulus  
file,  use the following pin names only.  These are the only ones that MPSIM  
recognizes as valid I/O pins: 
   -    MCLR 
   -    RA0-RA5 
   -    RB0-RB7 
   -    RC0-RC7 
 
Interrupts 
MPSIM version 4.5 or greater supports all interrupts on the PIC16C65: 
   -   Timer0 overflow 
   -   Timer1 overflow 
   -   Timer2  
   -   CCP1 
   -   CCP2 
   -   SSP (in SPI mode ONLY) 
   -   Change on Port RB <7:4> 
   -   External interrupt from RB0/INT pin 
   -   USART  
   -   Parallel Slave Port 
 
 
CPU Model 
 
Reset Conditions 
All reset conditions are supported by MPSIM.   
 
A Power-On-Reset can be simulated by using the RS instruction.  All special- 
purpose registers will be initialized to the values specified in the data  
sheet. 
 
A MCLR reset during normal operation or during SLEEP can easily be simulated  
by driving the MCLR pin low (and then high) via the stimulus file or by using  
the SE command or by using DK command.   
 
A WDT time-out reset is simulated when WDT is enabled (see DW command) and  
proper prescaler is set (by initializing OPTION register appropriately) and  
WDT actually overflows. WDT time-out period (with prescale = 1) is  
approximated at 18 ms (to closest instruction cycle multiple).  
 
The Time-out (TO) and Power-down (PD) bits in the Status register reflect  
appropriate reset condition.  This feature is useful for simulating various  
power-up and time out forks in the user code. 
 
Sleep 
MPSIM simulates the SLEEP instruction, and will appear asleep until a wake-up  
from sleep condition occurs.  For example, if the Watchdog timer has been  
enabled, it will wake the processor up from sleep when it times out (depending  
upon the prescaler setting in the OPTION register).  Another example of a  
wake-up-from-sleep condition, would be Timer1 wake-up from sleep.  In this  
case, when the processor is asleep, Timer1 would continue to increment until  
it overflows, and if the interrupt is enabled, will wake the processor on  
overflow and branch to the interrupt vector. 
 
WDT 
The Watchdog timer is fully simulated in the MPSIM simulator.  Because it is  
fuse-selectable on the device, it must be enabled by a separate command (see  
the DW command) in MPSIM.  The period of the WDT is determined by the  
prescaler settings in the OPTION register. The basic period (with prescaler =  
1) is approximated at 18 ms (to closest instruction cycle multiple). 
 
Stack 
MPSIM presents an accurate simulation of the hardware stack on the PIC16CXX,  
and additionally provides warning messages if an underflow or overflow  
condition occurs.  When a CALL instruction is encountered, or when an  
interrupt has occurred, the value of the PC+ 1 is pushed to the stack, and the  
stack is popped when a RETLW, RETURN, or RETFIE instruction is executed.  If  
more than eight values are pushed to the stack before it is popped, the value  
will be pushed to the stack, but a warning message will be issued, indicating  
a stack overflow condition.  An error message will also be generated if the  
user attempts to pop an empty stack.  Popping an empty stack will cause the  
stack pointer to point to the top of a full stack, and will not generate an  
error message if another pop is initiated. 
 
Special Registers 
To aid in debugging this device, certain items that are normally not  
observable have been declared as special registers.    Prescalers and  
postscalers cannot be declared in your code as registers, so there are special  
labels that can be added to the view screen.  You can add them as you normally  
would any other register declared in your code,  specifying any radix to view  
them. 
 
The following are special items that can be added to the view screen when the  
PIC16C65 has been selected: 
   -  T0PRE - Prescaler for timer0 
   -  T1PRE - Prescaler for timer1 
   -  T2PRE - Prescaler for timer2 
   -  T2POS - Postscaler for timer2 
   -  CCP1PRE - Prescaler for CCP1 
   -  CCP2PRE - Prescaler for CCP2 
   -  SPIPRE - Prescaler for SPI 
   -  SSPSR - SSP Shift register 
 
Please remember that these labels are only available when the PIC16C65 is the  
target processor, and that they cannot be manually modified. 
 
Peripherals 
 
Peripherals Supported 
Along with providing core support, the following peripheral modules (in  
addition to general-purpose I/O) are supported: 
   -  Timer0 
   -  Timer1 
   -  Timer2 
   -  CCP 
   -  CCP2 
   -  Parallel Slave Port 
   -  SSP (in SPI Mode only) 
   -  USART (limited) 
 
Tcycle Limitation 
It is important to remember that because MPSIM executes on instruction cycle  
boundaries, resolutions below 1 Tcy cannot be simulated.  Please see the  
following section for more details concerning the limitations of T-cycle  
simulation. 
 
MPSIM is a discrete-event simulator where all stimuli are evaluated and all  
response generated at instruction boundaries or Tcy.  One Tcy = 4 Tosc (where  
Tosc is input clock).  Therefore, there are several events that can not be  
accurately simulated in MPSIM.  These fall into two categories: 
   -  Purely asynchronous events 
   -  Synchronous events that occur at Tosc clock boundaries 
 
Because of this, the following items are not supported in MPSIM: 
   -  Timer0, Timer1, and Timer2 prescalers are capable of accepting clock  
pulse inputs smaller than Tcy, but these can not be simulated. 
   -  Capture input pulses can be smaller than one Tcy, but can not be  
simulated. 
   -  PWM output pulse resolution less than 1 Tcy is not supported. 
   -  8-bit compare will not be supported since the output resolution is  
limited to T cycles 
   -  In unsynchronized counter mode, clock input smaller than Tcy is not  
supported 
   -  The oscillator on RC0/RC1 pins is not supported.  The user can, however,  
simply use an external clock input for simulation purposes. 
 
In summary, the net result of instruction boundary simulation is that all  
events get synchronized at instruction boundary and events smaller than one  
instruction cycle get lost. 
 
TIMER0 
Timer0 (and the interrupt it can generate on overflow) is fully supported by  
MPSIM, and will increment by the internal or external clock.  Clock input must  
have a minimum high time of 1Tcy and a minimum low time of 1Tcy due to  
stimulus file requirements.  The prescaler for Timer0 is made accessible as  
T0PRE. It can be watched and modified. 
 
TIMER1 
Timer1 in its various modes is supported by MPSIM, except when running in  
counter mode by an external crystal.  The interrupt it can be generated on  
overflow and wake-up from sleep through interrupt are both supported by MPSIM.   
The prescaler for Timer1 is viewable and modifiable as T1PRE. The external  
oscillator on RC0/RC1 is not  simulated. The user can simply use a clock input  
(see CK command). 
 
TIMER2  
Timer2 and the interrupt that can be generated on overflow are fully supported  
by MPSIM, and both the prescaler and postscaler for Timer2 are viewable and  
modifiable (T2PRE and T2POS).  
CCP1 and CCP2 
 
CAPTURE 
MPSIM fully supports capture and the interrupt generated.  The prescaler for  
the CCP module is viewable and modifiable (CCP1PRE). 
 
COMPARE  
Compare mode, its interrupt, and the special event trigger (resetting Timer1  
if CCP1 and starting A/D Conversion if CCP2) are supported in this version of  
MPSIM. 
 
PWM 
PWM output (resolution greater than 1Tcy only) are supported in this version  
of MPSIM. 
 
SSP 
The Synchronous Serial Port is supported in SPI mode only.  The shift register  
(SSPSR) can be added to the viewscreen, observed and modified.  MPSIM  
currently does not support the I2C mode. 
 
USART 
Timing and interrupt generation is supported. Baud rate generator is  
supported. Reading and writing of the registers are supported but actual  
receive or transmit operation is not simulated.  
 
 
PIC16C71 User's Guide Addendum 
 
Introduction 
MPSIM provides support for more than one family of Microchip microcontrollers.   
This section has been added as an addendum to the MPSIM user's guide to  
centralize PIC16C71-specific simulator support.    
 
I/O Pins 
The PIC16C71 is an 18-pin device, with some of the I/O pins multiplexed with  
other peripherals (and therefore referred by more than one name).  When  
modifying pins either manually (e.g. with the SE command) or via the stimulus  
file,  use the following pin names only.  These are the only ones that MPSIM  
recognizes as valid I/O pins: 
   -  MCLR 
   -  RA0-RA4 
   -  RB0-RB7 
Additionally, RTCC is also recognized as Timer0 (previously RTCC) input, i.e.  
same as RA4. 
 
Interrupts 
MPSIM supports all interrupts on the PIC16C71: 
   -  Timer0 (RTCC) overflow 
   -  Change on Port RB <7..4> 
   -  External interrupt from RB0/INT pin 
   -  A/D interrupt complete 
 
CPU Model 
 
Reset Conditions 
All reset conditions are supported by MPSIM.   
A Power-On-Reset can be simulated by using the RS instruction.  All special- 
purpose registers will be initialized to the values specified in the data  
sheet. 
A MCLR reset during normal operation or during SLEEP can easily be simulated  
by driving the MCLR pin low (and then high) via the stimulus file or by using  
the SE command or by using DK command.   
A WDT time-out reset is simulated when WDT is enabled (see DW command) and  
proper prescaler is set (by initializing OPTION register appropriately) and  
WDT actually overflows. WDT time-out period (with prescale = 1) is  
approximated at 18 ms (to closest instruction cycle multiple).  
The Time-out (TO) and Power-down (PD) bits in the Status register reflect  
appropriate reset condition.  This feature is useful for simulating various  
power-up and time out forks in the user code. 
 
Sleep 
MPSIM simulates the SLEEP instruction, and will appear asleep until a wake-up  
from sleep condition occurs.  For example, if the Watchdog timer has been  
enabled, it will wake the processor up from sleep when it times out (depending  
upon the prescaler setting in the OPTION register).  Another example of a  
wake-up-from-sleep condition, would be wake-up due to RB0/INT external  
interrupt.  
 
WDT 
The Watchdog timer is fully simulated in the MPSIM simulator.  Because it is  
fuse-selectable on the device, it must be enabled by a separate command (see  
the DW command) in MPSIM.  The period of the WDT is determined by the  
prescaler settings in the OPTION register. The basic period (with prescaler =  
1) is approximated at 18 ms (to closest instruction cycle multiple). 
 
Stack 
MPSIM presents an accurate simulation of the hardware stack on the PIC16CXX,  
and additionally provides warning messages if an underflow or overflow  
condition occurs.  When a CALL instruction is encountered, or when an  
interrupt has occurred, the value of the PC+ 1 is pushed to the stack, and the  
stack is popped when a RETLW, RETURN, or RETFIE instruction is executed.  If  
more than eight values are pushed to the stack before it is popped, the value  
will be pushed to the stack, but a warning message will be issued, indicating  
a stack overflow condition.  An error message will also be generated if the  
user attempts to pop an empty stack.  Popping an empty stack will cause the  
stack pointer to point to the top of a full stack, and will not generate an  
error message if another pop is initiated. 
Special Registers 
To aid in debugging this device, certain items that are normally not  
observable have been declared as special registers.    Prescalers and  
postscalers cannot be declared in your code as registers, so there are special  
labels that can be added to the view screen.  You can add them as you normally  
would any other register declared in your code,  specifying any radix to view  
them. 
The following are special items that can be added to the view screen when the  
PIC16C71 has been selected: 
   -  T0PRE - Prescaler for timer0 
Please remember that these labels are only available when the PIC16C71 is the  
target processor, and that they cannot be manually modified. 
 
Peripherals 
 
Peripherals Supported 
Along with providing core support, the following peripheral modules (in  
addition to general-purpose I/O) are supported: 
   -  Timer0 
   -  A/D module (limited) 
 
Tcycle Limitation 
It is important to remember that because MPSIM executes on instruction cycle  
boundaries, resolutions below 1 Tcy cannot be simulated.  Please see the  
following section for more details concerning the limitations of T-cycle  
simulation. 
MPSIM is a discrete-event simulator where all stimuli are evaluated and all  
response generated at instruction boundaries or Tcy.  One Tcy = 4 Tosc (where  
Tosc is input clock).  Therefore, there are several events that can not be  
accurately simulated in MPSIM.  These fall into two categories: 
   -  Purely asynchronous events 
   -  Synchronous events that occur at Tosc clock boundaries 
Because of this, the following items are not supported in MPSIM: 
   -  Timer0 prescaler is capable of accepting clock pulse inputs smaller than  
Tcy, but this can not be simulated. 
In summary, the net result of instruction boundary simulation is that all  
events get synchronized at instruction boundary and events smaller than one  
instruction cycle get lost. 
 
TIMER0 
Timer0 (and the interrupt it can generate on overflow) is fully supported by  
MPSIM, and will increment by the internal or external clock.  Clock input must  
have a minimum high time of 1Tcy and a minimum low time of 1Tcy due to  
stimulus file requirements.  The prescaler for Timer0 is made accessible as  
T0PRE. It can be watched and modified. 
 
A/D Converter 
All the registers, timing function and interrupt generation are implemented.  
The simulator, however, does not load any meaningful value into A/D result  
register (ADRES) at the end of a conversion. Use the FI command to load the  
ADRES register from a file for simulation purposes. 
 
 
PIC16C73 User's Guide Addendum 
 
Introduction 
MPSIM provides support for more than one family of Microchip microcontrollers.   
This section has been added as an addendum to the MPSIM user's guide to  
centralize PIC16C73-specific simulator support.    
 
I/O Pins 
The PIC16C73 is a 28-pin device, with many of the I/O pins multiplexed with  
other peripherals (and therefore referred by more than one name).  When  
modifying pins either manually (e.g. with the SE command) or via the stimulus  
file,  use the following pin names only.  These are the only ones that MPSIM  
recognizes as valid I/O pins: 
   -  MCLR 
   -  RA0-RA5 
   -  RB0-RB7 
   -  RC0-RC7 
 
Interrupts 
MPSIM version 4.5 or greater supports all interrupts on the PIC16C73: 
   -  Timer0 overflow 
   -  Timer1 overflow 
   -  Timer2  
   -  CCP1 
   -  CCP2 
   -  SSP (in SPI mode ONLY) 
   -  Change on Port RB <7..4> 
   -  External interrupt from RB0/INT pin 
   -  A/D interrupt complete 
   -  USART  
 
CPU Model 
 
Reset Conditions 
All reset conditions are supported by MPSIM.   
A Power-On-Reset can be simulated by using the RS instruction.  All special- 
purpose registers will be initialized to the values specified in the data  
sheet. 
 
A MCLR reset during normal operation or during SLEEP can easily be simulated  
by driving the MCLR pin low (and then high) via the stimulus file or by using  
the SE command or by using DK command.   
 
A WDT time-out reset is simulated when WDT is enabled (see DW command) and  
proper prescaler is set (by initializing OPTION register appropriately) and  
WDT actually overflows. WDT time-out period (with prescale = 1) is  
approximated at 18 ms (to closest instruction cycle multiple).  
 
The Time-out (TO) and Power-down (PD) bits in the Status register reflect  
appropriate reset condition.  This feature is useful for simulating various  
power-up and time out forks in the user code. 
 
Sleep 
MPSIM simulates the SLEEP instruction, and will appear asleep until a wake-up  
from sleep condition occurs.  For example, if the Watchdog timer has been  
enabled, it will wake the processor up from sleep when it times out (depending  
upon the prescaler setting in the OPTION register).  Another example of a  
wake-up-from-sleep condition, would be Timer1 wake-up from sleep.  In this  
case, when the processor is asleep, Timer1 would continue to increment until  
it overflows, and if the interrupt is enabled, will wake the processor on  
overflow and branch to the interrupt vector. 
 
WDT 
The Watchdog timer is fully simulated in the MPSIM simulator.  Because it is  
fuse-selectable on the device, it must be enabled by a separate command (see  
the DW command) in MPSIM.  The period of the WDT is determined by the  
prescaler settings in the OPTION register. The basic period (with prescaler =  
1) is approximated at 18 ms (to closest instruction cycle multiple). 
 
Stack 
MPSIM presents an accurate simulation of the hardware stack on the PIC16CXX,  
and additionally provides warning messages if an underflow or overflow  
condition occurs.  When a CALL instruction is encountered, or when an  
interrupt has occurred, the value of the PC+ 1 is pushed to the stack, and the  
stack is popped when a RETLW, RETURN, or RETFIE instruction is executed.  If  
more than eight values are pushed to the stack before it is popped, the value  
will be pushed to the stack, but a warning message will be issued, indicating  
a stack overflow condition.  An error message will also be generated if the  
user attempts to pop an empty stack.  Popping an empty stack will cause the  
stack pointer to point to the top of a full stack, and will not generate an  
error message if another pop is initiated. 
 
 
Special Registers 
To aid in debugging this device, certain items that are normally not  
observable have been declared as special registers.    Prescalers and  
postscalers cannot be declared in your code as registers, so there are special  
labels that can be added to the view screen.  You can add them as you normally  
would any other register declared in your code,  specifying any radix to view  
them. 
 
The following are special items that can be added to the view screen when the  
PIC16C73 has been selected: 
   -  T0PRE - Prescaler for TIMER0 
   -  T1PRE - Prescaler for timer1 
   -  T2PRE - Prescaler for timer2 
   -  T2POS - Postscaler for timer2 
   -  CCP1PRE - Prescaler for CCP1 
   -  CCP2PRE - Prescaler for CCP2 
   -  SPIPRE - Prescaler for SPI 
   -  SSPSR - SSP Shift register 
 
Please remember that these labels are only available when the PIC16C73 is the  
target processor, and that they cannot be manually modified. 
 
Peripherals 
 
Peripherals Supported 
Along with providing core support, the following peripheral modules (in  
addition to general-purpose I/O) are supported: 
   -  TIMER0 
   -  Timer1 
   -  Timer2 
   -  CCP 
   -  CCP2 
   -  SSP (in SPI Mode only) 
   -  A/D module (limited) 
   -  USART (limited) 
 
Tcycle Limitation 
It is important to remember that because MPSIM executes on instruction cycle  
boundaries, resolutions below 1 Tcy cannot be simulated.  Please see the  
following section for more details concerning the limitations of T-cycle  
simulation. 
 
MPSIM is a discrete-event simulator where all stimuli are evaluated and all  
response generated at instruction boundaries or Tcy.  One Tcy = 4 Tosc (where  
Tosc is input clock).  Therefore, there are several events that can not be  
accurately simulated in MPSIM.  These fall into two categories: 
   -  Purely asynchronous events 
   -  Synchronous events that occur at Tosc clock boundaries 
 
Because of this, the following items are not supported in MPSIM: 
   -  Timer0, Timer1, and Timer2 prescalers are capable of accepting clock  
pulse inputs smaller than Tcy, but these can not be simulated. 
   -  Capture input pulses can be smaller than one Tcy, but can not be  
simulated. 
   -  PWM output pulse resolution less than 1 Tcy is not supported. 
   -  8-bit compare will not be supported since the output resolution is  
limited to T cycles 
   -  In unsynchronized counter mode, clock input smaller than Tcy is not  
supported 
   -  The oscillator on RC0/RC1 pins is not supported.  The user can, however,  
simply use an external clock input for simulation purposes. 
In summary, the net result of instruction boundary simulation is that all  
events get synchronized at instruction boundary and events smaller than one  
instruction cycle get lost. 
 
TIMER0 
Timer0 (and the interrupt it can generate on overflow) is fully supported by  
MPSIM, and will increment by the internal or external clock.  Clock input must  
have a minimum high time of 1Tcy and a minimum low time of 1Tcy due to  
stimulus file requirements.  The prescaler for Timer0 is made accessible as  
T0PRE. It can be watched and modified. 
 
TIMER1 
Timer1 in its various modes is supported by MPSIM, except when running in  
counter mode by an external crystal.  The interrupt it can be generated on  
overflow and wake-up from sleep through interrupt are both supported by MPSIM.   
The prescaler for Timer1 is viewable and modifiable as T1PRE. The external  
oscillator on RC0/RC1 is not  simulated. The user can simply use a clock input  
(see CK command). 
 
TIMER2  
Timer2 and the interrupt that can be generated on overflow are fully supported  
by MPSIM, and both the prescaler and postscaler for Timer2 are viewable and  
modifiable (T2PRE and T2POS).  
CCP1 and CCP2 
 
CAPTURE 
MPSIM fully supports capture and the interrupt generated.  The prescaler for  
the CCP module is viewable and modifiable (CCP1PRE). 
 
COMPARE  
Compare mode, its interrupt, and the special event trigger (resetting Timer1  
if CCP1 and starting A/D Conversion if CCP2) are supported in this version of  
MPSIM. 
 
PWM 
PWM output (resolution greater than 1Tcy only) are supported in this version  
of MPSIM. 
 
SSP 
The Synchronous Serial Port is supported in SPI mode only.  The shift register  
(SSPSR) can be added to the viewscreen, observed and modified.  MPSIM  
currently does not support the I2C mode. 
 
USART 
Timing and interrupt generation is supported. Baud rate generator is  
supported. Reading and writing of the registers are supported but actual  
receive or transmit operation is not simulated.  
 
A/D Converter 
All the registers, timing function and interrupt generation are implemented.  
The simulator, however, does not load any meaningful value into A/D result  
register (ADRES) at the end of a conversion. Use the FI command to load the  
ADRES register from a file for simulation purposes. 
 
 
 
PIC16C74 User's Guide Addendum 
 
Introduction 
MPSIM provides support for more than one family of Microchip microcontrollers.   
This section has been added as an addendum to the MPSIM user's guide to  
centralize PIC16C74-specific simulator support.    
 
I/O Pins 
The PIC16C74 is a 40-pin device, with many of the I/O pins multiplexed with  
other peripherals (and therefore referred by more than one name).  When  
modifying pins either manually (e.g. with the SE command) or via the stimulus  
file,  use the following pin names only.  These are the only ones that MPSIM  
recognizes as valid I/O pins: 
   -  MCLR 
   -  RA0-RA5 
   -  RB0-RB7 
   -  RC0-RC7 
   -  RD0-RD7 
   -  RE0-RE2 
 
Interrupts 
MPSIM version 4.5 or greater supports all interrupts on the PIC16C74: 
   -  Timer0 overflow 
   -  Timer1 overflow 
   -  Timer2  
   -  CCP1 
   -  CCP2 
   -  SSP (in SPI mode ONLY) 
   -  Change on Port RB <7..4> 
   -  External interrupt from RB0/INT pin 
   -  A/D interrupt complete 
   -  USART  
   -  Parallel Slave Port 
 
CPU Model 
 
Reset Conditions 
All reset conditions are supported by MPSIM.   
A Power-On-Reset can be simulated by using the RS instruction.  All special- 
purpose registers will be initialized to the values specified in the data  
sheet. 
 
A MCLR reset during normal operation or during SLEEP can easily be simulated  
by driving the MCLR pin low (and then high) via the stimulus file or by using  
the SE command or by using DK command.   
 
A WDT time-out reset is simulated when WDT is enabled (see DW command) and  
proper prescaler is set (by initializing OPTION register appropriately) and  
WDT actually overflows. WDT time-out period (with prescale = 1) is  
approximated at 18 ms (to closest instruction cycle multiple).  
 
The Time-out (TO) and Power-down (PD) bits in the Status register reflect  
appropriate reset condition.  This feature is useful for simulating various  
power-up and time out forks in the user code. 
 
Sleep 
MPSIM simulates the SLEEP instruction, and will appear asleep until a wake-up  
from sleep condition occurs.  For example, if the Watchdog timer has been  
enabled, it will wake the processor up from sleep when it times out (depending  
upon the prescaler setting in the OPTION register).  Another example of a  
wake-up-from-sleep condition, would be Timer1 wake-up from sleep.  In this  
case, when the processor is asleep, Timer1 would continue to increment until  
it overflows, and if the interrupt is enabled, will wake the processor on  
overflow and branch to the interrupt vector. 
 
WDT 
The Watchdog timer is fully simulated in the MPSIM simulator.  Because it is  
fuse-selectable on the device, it must be enabled by a separate command (see  
the DW command) in MPSIM.  The period of the WDT is determined by the  
prescaler settings in the OPTION register. The basic period (with prescaler =  
1) is approximated at 18 ms (to closest instruction cycle multiple). 
 
Stack 
MPSIM presents an accurate simulation of the hardware stack on the PIC16CXX,  
and additionally provides warning messages if an underflow or overflow  
condition occurs.  When a CALL instruction is encountered, or when an  
interrupt has occurred, the value of the PC+ 1 is pushed to the stack, and the  
stack is popped when a RETLW, RETURN, or RETFIE instruction is executed.  If  
more than eight values are pushed to the stack before it is popped, the value  
will be pushed to the stack, but a warning message will be issued, indicating  
a stack overflow condition.  An error message will also be generated if the  
user attempts to pop an empty stack.  Popping an empty stack will cause the  
stack pointer to point to the top of a full stack, and will not generate an  
error message if another pop is initiated. 
 
Special Registers 
To aid in debugging this device, certain items that are normally not  
observable have been declared as special registers.    Prescalers and  
postscalers cannot be declared in your code as registers, so there are special  
labels that can be added to the view screen.  You can add them as you normally  
would any other register declared in your code,  specifying any radix to view  
 
them. 
The following are special items that can be added to the view screen when the  
PIC16C74 has been selected: 
   -  T0PRE - Prescaler for TIMER0 
   -  T1PRE - Prescaler for timer1 
   -  T2PRE - Prescaler for timer2 
   -  T2POS - Postscaler for timer2 
   -  CCP1PRE - Prescaler for CCP1 
   -  CCP2PRE - Prescaler for CCP2 
   -  SPIPRE - Prescaler for SPI 
   -  SSPSR - SSP Shift register 
Please remember that these labels are only available when the PIC16C74 is the  
target processor, and that they cannot be manually modified. 
 
Peripherals 
 
Peripherals Supported 
Along with providing core support, the following peripheral modules (in  
addition to general-purpose I/O) are supported: 
   -  TIMER0 
   -  Timer1 
   -  Timer2 
   -  CCP 
   -  CCP2 
   -  Parallel Slave Port 
   -  SSP (in SPI Mode only) 
   -  A/D module (limited) 
   -  USART (limited) 
 
Tcycle Limitation 
It is important to remember that because MPSIM executes on instruction cycle  
boundaries, resolutions below 1 Tcy cannot be simulated.  Please see the  
following section for more details concerning the limitations of T-cycle  
simulation. 
 
MPSIM is a discrete-event simulator where all stimuli are evaluated and all  
response generated at instruction boundaries or Tcy.  One Tcy = 4 Tosc (where  
Tosc is input clock).  Therefore, there are several events that can not be  
accurately simulated in MPSIM.  These fall into two categories: 
   -  Purely asynchronous events 
   -  Synchronous events that occur at Tosc clock boundaries 
 
Because of this, the following items are not supported in MPSIM: 
   -  Timer0, Timer1, and Timer2 prescalers are capable of accepting clock  
pulse inputs smaller than Tcy, but these can not be simulated. 
   -  Capture input pulses can be smaller than one Tcy, but can not be  
simulated. 
   -  PWM output pulse resolution less than 1 Tcy is not supported. 
   -  8-bit compare will not be supported since the output resolution is  
limited to T cycles 
   -  In unsynchronized counter mode, clock input smaller than Tcy is not  
supported 
   -  The oscillator on RC0/RC1 pins is not supported.  The user can, however,  
simply use an external clock input for simulation purposes. 
In summary, the net result of instruction boundary simulation is that all  
events get synchronized at instruction boundary and events smaller than one  
instruction cycle get lost. 
 
TIMER0 
Timer0 (and the interrupt it can generate on overflow) is fully supported by  
MPSIM, and will increment by the internal or external clock.  Clock input must  
have a minimum high time of 1Tcy and a minimum low time of 1Tcy due to  
stimulus file requirements.  The prescaler for Timer0 is made accessible as  
T0PRE. It can be watched and modified. 
 
TIMER1 
Timer1 in its various modes is supported by MPSIM, except when running in  
counter mode by an external crystal.  The interrupt it can be generated on  
overflow and wake-up from sleep through interrupt are both supported by MPSIM.   
The prescaler for Timer1 is viewable and modifiable as T1PRE. The external  
oscillator on RC0/RC1 is not  simulated. The user can simply use a clock input  
(see CK command). 
 
TIMER2  
Timer2 and the interrupt that can be generated on overflow are fully supported  
by MPSIM, and both the prescaler and postscaler for Timer2 are viewable and  
modifiable (T2PRE and T2POS).  
CCP1 and CCP2 
 
CAPTURE 
MPSIM fully supports capture and the interrupt generated.  The prescaler for  
the CCP module is viewable and modifiable (CCP1PRE). 
 
COMPARE  
Compare mode, its interrupt, and the special event trigger (resetting Timer1  
if CCP1 and starting A/D Conversion if CCP2) are supported in this version of  
MPSIM. 
 
PWM 
PWM output (resolution greater than 1Tcy only) are supported in this version  
of MPSIM. 
 
SSP 
The Synchronous Serial Port is supported in SPI mode only.  The shift register  
(SSPSR) can be added to the viewscreen, observed and modified.  MPSIM  
currently does not support the I2C mode. 
 
USART 
Timing and interrupt generation is supported. Baud rate generator is  
supported. Reading and writing of the registers are supported but actual  
receive or transmit operation is not simulated.  
 
A/D Converter 
All the registers, timing function and interrupt generation are implemented.  
The simulator, however, does not load any meaningful value into A/D result  
register (ADRES) at the end of a conversion. Use the FI command to load the  
ADRES register from a file for simulation purposes. 
 
 
 
PIC16C84 User's Guide Addendum 
 
Introduction 
MPSIM provides support for more than one family of Microchip microcontrollers.   
This section has been added as an addendum to the MPSIM user's guide to  
centralize PIC16C74-specific simulator support.    
 
I/O Pins 
The PIC16C84 is an 18-pin device, with some of the I/O pins multiplexed with  
other peripherals (and therefore referred by more than one name).  When  
modifying pins either manually (e.g. with the SE command) or via the stimulus  
file,  use the following pin names only.  These are the only ones that MPSIM  
recognizes as valid I/O pins: 
   -  MCLR 
   -  RA0-RA4 
   -  RB0-RB7 
Additionally, RTCC is also recognized as Timer0 (previously RTCC) input, i.e.  
same as RA4. 
 
Interrupts 
MPSIM supports all interrupts on the PIC16C71: 
   -  Timer0 overflow 
   -  Change on Port RB <7..4> 
   -  External interrupt from RB0/INT pin 
   -  EEPROM write complete 
 
CPU Model 
 
Reset Conditions 
All reset conditions are supported by MPSIM.   
A Power-On-Reset can be simulated by using the RS instruction.  All special- 
purpose registers will be initialized to the values specified in the data  
sheet. 
 
A MCLR reset during normal operation or during SLEEP can easily be simulated  
by driving the MCLR pin low (and then high) via the stimulus file or by using  
the SE command or by using DK command.   
 
A WDT time-out reset is simulated when WDT is enabled (see DW command) and  
proper prescaler is set (by initializing OPTION register appropriately) and  
WDT actually overflows. WDT time-out period (with prescale = 1) is  
approximated at 18 ms (to closest instruction cycle multiple).  
 
The Time-out (TO) and Power-down (PD) bits in the Status register reflect  
appropriate reset condition.  This feature is useful for simulating various  
power-up and time out forks in the user code. 
 
Sleep 
MPSIM simulates the SLEEP instruction, and will appear asleep until a wake-up  
from sleep condition occurs.  For example, if the Watchdog timer has been  
enabled, it will wake the processor up from sleep when it times out (depending  
upon the prescaler setting in the OPTION register).  Another example of a  
wake-up-from-sleep condition, would be due to RB0/INT interrupt wake-up.  
 
WDT 
The Watchdog timer is fully simulated in the MPSIM simulator.  Because it is  
fuse-selectable on the device, it must be enabled by a separate command (see  
the DW command) in MPSIM.  The period of the WDT is determined by the  
prescaler settings in the OPTION register. The basic period (with prescaler =  
1) is approximated at 18 ms (to closest instruction cycle multiple). 
 
Stack 
MPSIM presents an accurate simulation of the hardware stack on the PIC16CXX,  
and additionally provides warning messages if an underflow or overflow  
condition occurs.  When a CALL instruction is encountered, or when an  
interrupt has occurred, the value of the PC+ 1 is pushed to the stack, and the  
stack is popped when a RETLW, RETURN, or RETFIE instruction is executed.  If  
more than eight values are pushed to the stack before it is popped, the value  
will be pushed to the stack, but a warning message will be issued, indicating  
a stack overflow condition.  An error message will also be generated if the  
user attempts to pop an empty stack.  Popping an empty stack will cause the  
stack pointer to point to the top of a full stack, and will not generate an  
error message if another pop is initiated. 
 
Special Registers 
To aid in debugging this device, certain items that are normally not  
observable have been declared as special registers.    Prescalers and  
postscalers cannot be declared in your code as registers, so there are special  
labels that can be added to the view screen.  You can add them as you normally  
would any other register declared in your code,  specifying any radix to view  
them. 
 
The following are special items that can be added to the view screen when the  
PIC16C84 has been selected: 
   -  T0PRE - Prescaler for TIMER0 
 
Please remember that these labels are only available when the PIC16C84 is the  
target processor, and that they cannot be manually modified. 
 
Peripherals 
 
Peripherals Supported 
Along with providing core support, the following peripheral modules (in  
addition to general-purpose I/O) are supported: 
   -  TIMER0 
   -  EEPROM data memory 
 
Tcycle Limitation 
It is important to remember that because MPSIM executes on instruction cycle  
boundaries, resolutions below 1 Tcy cannot be simulated.  Please see the  
following section for more details concerning the limitations of T-cycle  
simulation. 
 
MPSIM is a discrete-event simulator where all stimuli are evaluated and all  
response generated at instruction boundaries or Tcy.  One Tcy = 4 Tosc (where  
Tosc is input clock).  Therefore, there are several events that can not be  
accurately simulated in MPSIM.  These fall into two categories: 
   -  Purely asynchronous events 
   -  Synchronous events that occur at Tosc clock boundaries 
 
Because of this, the following items are not supported in MPSIM: 
   -  Timer0 prescaler is capable of accepting clock pulse inputs smaller than  
Tcy, but this can not be simulated. 
 
In summary, the net result of instruction boundary simulation is that all  
events get synchronized at instruction boundary and events smaller than one  
instruction cycle get lost. 
 
TIMER0 
Timer0 (and the interrupt it can generate on overflow) is fully supported by  
MPSIM, and will increment by the internal or external clock.  Clock input must  
have a minimum high time of 1Tcy and a minimum low time of 1Tcy due to  
stimulus file requirements.  The prescaler for Timer0 is made accessible as  
T0PRE. It can be watched and modified. 
 
EEPROM Data Memory  
The EEPROM data memory is fully simulated. The registers and the read/write  
cycles are fully implemented. The write cycle time is approximated to 10 ms  
(to nearest instruction cycle multiple). 
Please note that wheras the write to EEPROM is supported, the simulator does  
not check for "the valid instruction sequence". The simulator does, however,  
simulate functions of WRERR and WREN control bits in the EECON1 register. 
 
 
 
PIC17C42 User's Guide Addendum 
 
Introduction 
MPSIM provides support for more than one family of Microchip microcontrollers.   
This section has been added as an addendum to the MPSIM user's guide to  
centralize PIC17C42-specific simulator support.    
 
I/O Pins 
The PIC17C42 is a 33-pin device, with many of the I/O pins multiplexed with  
other peripherals (and therefore referred by more than one name).  When  
modifying pins either manually (with the SE command) or via the stimulus file,   
use the following pin names only.  These are the only ones that MPSIM  
recognizes as valid I/O pins: 
   -  MCLR 
   -  RTCC 
   -  RA0-RA5 
   -  RB0-RB7 
   -  RC0-RC7 
   -  RD0-RD7 
   -  RE0-RE2 
 
Special Function Registers 
Many special-function registers in the 17CXX family (specifically the  
peripheral registers) are located in register banks other than bank zero.  To  
access these registers in your program, you must first select the desired bank  
and then specify the address within that bank (0x10 - 0x17).  Because of this,  
the porta register (address 0x10 in bank 0), for example, and the ddrc  
(address 0x10 in bank 1) registers would both be defined in your source code  
as addresses 0x10.   
 
In order to distinguish between labels that have the same address, MPSIM has  
pre-defined the following labels with file register addresses and has added  
them to its internal symbol table: 
   DDRC   TMR1   PW1DCL 
   PORTC  TMR2   PW2DCL 
   DDRD   TMR3L  PW1DCH 
   PORTD  TMR3H  PW2DCH 
   DDRE   PR1    CA2L 
   PORTE  PR2    CA2H 
   PIR    PR3L   TCON1 
   PIE    PR3H   TCON2 
 
If you want to view the contents of any of these registers during your  
simulation session, you can add them to the viewscreen by using the AD  
command.   
 
Interrupts 
MPSIM Version 5.0 or greater supports all interrupts on the PIC17C42: 
   -  External interrupt on INT pin 
   -  TMR0 overflow interrupt 
   -  External interrupt on RT pin 
   -  Port B input change interrupt 
   -  Timer/Counter1 interrupt 
   -  Timer/Counter2 interrupt 
   -  Timer/Counter3 interrupt 
   -  Capture1 interrupt 
   -  Capture2 Interrupt 
   -  Serial port transmit interrupt* 
   -  Serial port receive interrupt* 
           *Serial port timing only 
 
CPU Model 
 
Reset Conditions 
All reset conditions are supported by MPSIM 
A Power-On-Reset can be simulated by using the RS instruction.  all special- 
purpose registers will be initialized to the values specified in the data  
sheet. 
 
A MCLR reset during normal operation or during SLEEP can easily be simulated  
by driving the MCLR pin low (and then high) via the stimulus file, by using  
the SE command, or by using the DK command. 
 
A WDT time-out reset is simulated when the WDT is enabled (see DW command) and  
the proper prescaler is set (see the FW command) and the WDT actually  
overflows.  WDT time-out period is approximated at 12 ms (to closest  
instruction cycle multiple) but can be changed by using the WP command. 
 
The Time out (TO) and Power-Down (PD) bits in the ALUSTA register reflect  
appropriate reset condition.  This feature is useful for simulating various  
power-up and time-out forks in the user code. 
 
Sleep 
MPSIM simulates the SLEEP instruction and will appear asleep until a wake-up  
from sleep condition occurs.  For example, if the Watchdog timer has been  
enabled, it will wake the processor up from sleep when it times out (depending  
on the fuse setting by the FW command).  Another example of a wake-up-from- 
sleep condition, would be an input change on PORTB.  If the interrupt is  
enabled and the GLINTD bit is set, the processor will wake-up and will resume  
executing from the instruction following the SLEEP command.   If the GLINTD =  
0, the normal interrupt response will take place. 
 
WDT 
The Watchdog timer is fully simulated in the MPSIM simulator.  Because it is  
fuse-selectable and fuse-configurable on the device, it must be enabled and  
configured by separate commands (see the DW  and the FW commands) in MPSIM.   
The basic period of the WDT (with prescaler = 1) is approximated at 12ms (to  
closest instruction cycle multiple) but can also be changed via the WP  
command. 
 
Stack 
MPSIM presents an accurate simulation of the hardware stack on the PIC17CXX,  
and additionally provides warning messages if an underflow or overflow  
condition occurs.  When a CALL or LCALL instruction is encountered or when an  
interrupt has occurred, the value of the PC+ 1 is pushed to the stack. The  
stack is popped when a RETLW, RETURN, or RETFIE instruction is executed.  If  
more than sixteen values are pushed to the stack before it is popped, the  
value will be pushed to the stack, a warning message will be issued indicating  
a stack overflow condition, and the STAKAVL bit will be cleared until a reset  
condition occurs   
 
Instruction Set 
The entire 17CXX instruction set is supported, including pre-increment and  
post-increment of indirect-address registers (according to their  
configuration).  The TABLRD and TABLWT instructions are also fully supported,  
including long writes for the TABLWT instruction. 
 
Special Registers 
To aid in debugging this device, certain items that are normally not  
observable have been declared as special registers.  Prescalers cannot be  
declared in user code as registers, so there ar special labels that can be  
added to the view screen.  You can add them as you normally would any other  
register declared in your code, specifying any radix to view them. 
 
The following special items can be added to the view screen when the PIC17C42  
has been selected: 
   T0PRE (Prescaler for Timer 0) 
   WDTPRE (Prescaler for WDT) 
 
Peripherals 
Along with providing core support, the following peripheral modules (in  
addition to general-purpose I/O) are supported: 
   -  Timer 0 in both internal and external clock modes 
   -  Timer1 and Timer2 (and their respective period registers) 
   -  Timer3 
   -  Two Capture Modules 
   -  Two PWM Modules 
   -  USART (limited) 
 
Tcycle Limitation 
It is important to remember that because MPSIM executes on instruction cycle  
boundaries, resolutions below 1Tcy cannot be simulated.  Please see the  
following section for more details concerning the limitations of T-cycle  
simulation. 
 
MPSIM is a discrete-event simulator where all stimuli are evaluated an all  
response generated at instruction boundaries or Tcy.  One Tcy = 4 Tosc (where  
Tosc is input clock).  Therefor, there are several events that can not be  
accurately simulated in MPSIM.  These fall into two categories: 
   -  Purely asynchronous events 
   -  Synchronous events that occur at Tosc clock boundaries 
Because of this, the following items are not supported in MPSIM: 
   -  Timer0 prescaler is capable of accepting clock pulse inputs smaller than  
Tcy, but these can not be simulated. 
   -  Capture input pulses can be smaller than one Tcy, but can not be  
simulated. 
   -  PWM output pulse resolution less than 1Tcy is not supported 
   -  In unsynchronized counter mode, clock input smaller than Tcy is not  
supported. 
In summary, the net result of instruction boundary simulation is that all  
events get synchronized at instruction boundary and events smaller than one  
instruction cycle get lost. 
 
TIMER0 
Timer0 (and the interrupt it can generate on overflow) is fully supported by  
MPSIM, and will increment by the internal or external clock.  Delay from  
external clock edge to timer increment has also been simulated, as well as the  
interrupt latency period.  Clock input must have a minimum high time of 1Tcy  
and a minimum low time of 1Tcy due to the stimulus file requirements.  The  
prescaler for Timer0 is made accessible as T0PRE.  It can be watched and  
modified. 
 
TIMER1 and TIMER2 
Timer1 and Timer2 in its various modes is fully supported by MPSIM.  Delays  
from clock edge to increment (when configured to increment from rising or  
falling edge of external clock) is simulated as well as the interrupt latency  
periods. Clock input must have a minimum high time of 1Tcy and a minimum low  
time of 1Tcy due to the stimulus file requirements. 
 
TIMER3 and Capture 
MPSIM fully supports Timer3 and the Capture module in all of its modes.   
Delays from clock edge to increment (when configured in external mode), delay  
for capture and interrupt latency periods are fully supported. Clock input  
must have a minimum high time of 1Tcy and a minimum low time of 1Tcy due to  
the stimulus file requirements. 
 
PWM 
Both PWM outputs are supported (resolution greater than 1Tcy only) are  
supported in this version of MPSIM. 
 
USART 
Timing and interrupt generation is supported.  Baud rate generator is  
supported.  Reading and writing of the registers are supported but actual  
receive or transmit operation is not simulated. 
 
Memory Modes 
The following memory modes are supported by MPSIM: 
   -  Microcontroller Mode 
   -  Extended Microcontroller Mode 
   -  Microprocessor Mode 
The default is Microcontroller mode, which has 2K of program-memory on-chip.   
If you would like to use any of the other modes, you must use the FW command  
(since this option is fuse-selectable on chip).   
 
 
PIC17C43 User's Guide Addendum 
 
Introduction 
MPSIM provides support for more than one family of Microchip microcontrollers.   
This section has been added as an addendum to the MPSIM user's guide to  
centralize PIC17C43-specific simulator support.    
  
I/O Pins 
The PIC17C43 is a 33-pin device, with many of the I/O pins multiplexed with  
other peripherals (and therefore referred by more than one name).  When  
modifying pins either manually (with the SE command) or via the stimulus file,   
use the following pin names only.  These are the only ones that MPSIM  
recognizes as valid I/O pins: 
   -  MCLR 
   -  RTCC 
   -  RA0-RA5 
   -  RB0-RB7 
   -  RC0-RC7 
   -  RD0-RD7 
   -  RE0-RE2 
 
Special Function Registers 
Many special-function registers in the 17CXX family (specifically the  
peripheral registers) are located in register banks other than bank zero.  To  
access these registers in your program, you must first select the desired bank  
and then specify the address within that bank (0x10 - 0x17).  Because of this,  
the porta register (address 0x10 in bank 0), for example, and the ddrc  
(address 0x10 in bank 1) registers would both be defined in your source code  
as addresses 0x10.   
 
In order to distinguish between labels that have the same address, MPSIM has  
pre-defined the following labels with file register addresses and has added  
them to its internal symbol table: 
DDRC    TMR1   PW1DCL 
PORTC   TMR2   PW2DCL 
DDRD    TMR3L  PW1DCH 
PORTD   TMR3H  PW2DCH 
DDRE    PR1    CA2L 
PORTE   PR2    CA2H 
PIR     PR3L   TCON1 
PIE     PR3H   TCON2 
 
If you want to view the contents of any of these registers during your  
simulation session, you can add them to the viewscreen by using the AD  
command.   
 
Interrupts 
MPSIM Version 5.0 or greater supports all interrupts on the PIC17C43: 
   -  External interrupt on INT pin 
   -  TMR0 overflow interrupt 
   -  External interrupt on RT pin 
   -  Port B input change interrupt 
   -  Timer/Counter1 interrupt 
   -  Timer/Counter2 interrupt 
   -  Timer/Counter3 interrupt 
   -  Capture1 interrupt 
   -  Capture2 Interrupt 
   -  Serial port transmit interrupt* 
   -  Serial port receive interrupt* 
*Serial port timing only 
 
CPU Model 
 
Reset Conditions 
All reset conditions are supported by MPSIM 
 
A Power-On-Reset can be simulated by using the RS instruction.  all special- 
purpose registers will be initialized to the values specified in the data  
sheet. 
 
A MCLR reset during normal operation or during SLEEP can easily be simulated  
by driving the MCLR pin low (and then high) via the stimulus file, by using  
the SE command, or by using the DK command. 
 
A WDT time-out reset is simulated when the WDT is enabled (see DW command) and  
the proper prescaler is set (see the FW command) and the WDT actually  
overflows.  WDT time-out period is approximated at 12 ms (to closest  
instruction cycle multiple) but can be changed by using the WP command. 
 
The Time out (TO) and Power-Down (PD) bits in the ALUSTA register reflect  
appropriate reset condition.  This feature is useful for simulating various  
power-up and time-out forks in the user code. 
 
Sleep 
MPSIM simulates the SLEEP instruction and will appear asleep until a wake-up  
from sleep condition occurs.  For example, if the Watchdog timer has been  
enabled, it will wake the processor up from sleep when it times out (depending  
on the fuse setting by the FW command).  Another example of a wake-up-from- 
sleep condition, would be an input change on PORT B.  If the interrupt is  
enabled and the GLINTD bit is set, the processor will wake-up and will resume  
executing from the instruction following the SLEEP command.   If the GLINTD =  
0, the normal interrupt response will take place. 
 
WDT 
The Watchdog timer is fully simulated in the MPSIM simulator.  Because it is  
fuse-selectable and fuse-configurable on the device, it must be enabled and  
configured by separate commands (see the DW  and the FW commands) in MPSIM.   
The basic period of the WDT (with prescaler = 1) is approximated at 12ms (to  
closest instruction cycle multiple) but can also be changed via the WP  
command. 
 
Stack 
MPSIM presents an accurate simulation of the hardware stack on the PIC17CXX,  
and additionally provides warning messages if an underflow or overflow  
condition occurs.  When a CALL or LCALL instruction is encountered or when an  
interrupt has occurred, the value of the PC+ 1 is pushed to the stack. The  
stack is popped when a RETLW, RETURN, or RETFIE instruction is executed.  If  
more than sixteen values are pushed to the stack before it is popped, the  
value will be pushed to the stack, a warning message will be issued indicating  
a stack overflow condition, and the STAKAVL bit will be cleared until a reset  
condition occurs   
 
Instruction Set 
The entire 17CXX instruction set is supported, including pre-increment and  
post-increment of indirect-address registers (according to their  
configuration).  The TABLRD and TABLWT instructions are also fully supported,  
including long writes for the TABLWT instruction.  The hardware multiply  
instructions, MULLW and MULLWF are both fully supported as is the MOVLP  
instruction. 
 
Special Registers 
To aid in debugging this device, certain items that are normally not  
observable have been declared as special registers.  Prescalers cannot be  
declared in user code as registers, so there ar special labels that can be  
added to the view screen.  You can add them as you normally would any other  
register declared in your code, specifying any radix to view them. 
 
The following special item can be added to the view screen when the PIC17C43  
has been selected: 
T0PRE (Prescaler for Timer 0) 
WDTPRE (Prescaler for WDT)  
 
Peripherals 
Along with providing core support, the following peripheral modules (in  
addition to general-purpose I/O) are supported: 
   -  Timer 0 in both internal and external clock modes 
   -  Timer1 and Timer2 (and their respective period registers) 
   -  Timer3 
   -  Two Capture Modules 
   -  Two PWM Modules 
   -  USART (limited) 
 
Tcycle Limitation 
It is important to remember that because MPSIM executes on instruction cycle  
boundaries, resolutions below 1Tcy cannot be simulated.  Please see the  
following section for more details concerning the limitations of T-cycle  
simulation. 
 
MPSIM is a discrete-event simulator where all stimuli are evaluated an all  
response generated at instruction boundaries or Tcy.  One Tcy = 4 Tosc (where  
Tosc is input clock).  Therefor, there are several events that can not be  
accurately simulated in MPSIM.  These fall into two categories: 
   -  Purely asynchronous events 
   -  Synchronous events that occur at Tosc clock boundaries 
 
Because of this, the following items are not supported in MPSIM: 
   -  Timer0 prescaler is capable of accepting clock pulse inputs smaller than  
Tcy, but these can not be simulated. 
   -  Capture input pulses can be smaller than one Tcy, but can not be  
simulated. 
   -  PWM output pulse resolution less than 1Tcy is not supported 
   -  In unsynchronized counter mode, clock input smaller than Tcy is not  
supported. 
In summary, the net result of instruction boundary simulation is that all  
events get synchronized at instruction boundary and events smaller than one  
instruction cycle get lost. 
 
TIMER0 
Timer0 (and the interrupt it can generate on overflow) is fully supported by  
MPSIM, and will increment by the internal or external clock.  Delay from  
external clock edge to timer increment has also been simulated, as well as the  
interrupt latency period.  Clock input must have a minimum high time of 1Tcy  
and a minimum low time of 1Tcy due to the stimulus file requirements.  The  
prescaler for Timer0 is made accessible as T0PRE.  It can be watched and  
modified. 
 
TIMER1 and TIMER2 
Timer1 and Timer2 in its various modes is fully supported by MPSIM.  Delays  
from clock edge to increment (when configured to increment from rising or  
falling edge of external clock) is simulated as well as the interrupt latency  
periods. Clock input must have a minimum high time of 1Tcy and a minimum low  
time of 1Tcy due to the stimulus file requirements. 
 
TIMER3 and Capture 
MPSIM fully supports Timer3 and the Capture module in all of its modes.   
Delays from clock edge to increment (when configured in external mode), delay  
for capture and interrupt latency periods are fully supported. Clock input  
must have a minimum high time of 1Tcy and a minimum low time of 1Tcy due to  
the stimulus file requirements. 
 
PWM 
Both PWM outputs are supported (resolution greater than 1Tcy only) are  
supported in this version of MPSIM. 
 
USART 
Timing and interrupt generation is supported.  Baud rate generator is  
supported.  Reading and writing of the registers are supported but actual  
receive or transmit operation is not simulated. 
 
Memory Modes 
The following memory modes are supported by MPSIM: 
   -  Microcontroller Mode 
   -  Extended Microcontroller Mode 
   -  Microprocessor Mode 
 
The default is Microcontroller mode, which has 4K of program-memory on-chip.   
If you would like to use any of the other modes, you must use the FW command  
(since this option is fuse-selectable on chip).   
 
 
 
PIC17C44 User's Guide Addendum 
 
Introduction 
MPSIM provides support for more than one family of Microchip microcontrollers.   
This section has been added as an addendum to the MPSIM user's guide to  
centralize PIC17C44-specific simulator support.    
 
I/O Pins 
The PIC17C44 is a 33-pin device, with many of the I/O pins multiplexed with  
other peripherals (and therefore referred by more than one name).  When  
modifying pins either manually (with the SE command) or via the stimulus file,   
use the following pin names only.  These are the only ones that MPSIM  
recognizes as valid I/O pins: 
   -  MCLR 
   -  RTCC 
   -  RA0-RA5 
   -  RB0-RB7 
   -  RC0-RC7 
   -  RD0-RD7 
   -  RE0-RE2 
Special Function Registers 
Many special-function registers in the 17CXX family (specifically the  
peripheral registers) are located in register banks other than bank zero.  To  
access these registers in your program, you must first select the desired bank  
and then specify the address within that bank (0x10 - 0x17).  Because of this,  
the porta register (address 0x10 in bank 0), for example, and the ddrc  
(address 0x10 in bank 1) registers would both be defined in your source code  
as addresses 0x10.   
In order to distinguish between labels that have the same address, MPSIM has  
pre-defined the following labels with file register addresses and has added  
them to its internal symbol table: 
DDRC   TMR1   PW1DCL 
PORTC  TMR2   PW2DCL 
DDRD   TMR3L  PW1DCH 
PORTD  TMR3H  PW2DCH 
DDRE   PR1    CA2L 
PORTE  PR2    CA2H 
PIR    PR3L   TCON1 
PIE    PR3H   TCON2 
 
If you want to view the contents of any of these registers during your  
simulation session, you can add them to the viewscreen by using the AD  
command.   
 
Interrupts 
MPSIM Version 5.0 or greater supports all interrupts on the PIC17C44: 
   -  External interrupt on INT pin 
   -  TMR0 overflow interrupt 
   -  External interrupt on RT pin 
   -  Port B input change interrupt 
   -  Timer/Counter1 interrupt 
   -  Timer/Counter2 interrupt 
   -  Timer/Counter3 interrupt 
   -  Capture1 interrupt 
   -  Capture2 Interrupt 
   -  Serial port transmit interrupt* 
   -  Serial port receive interrupt* 
*Serial port timing only 
 
CPU Model 
 
Reset Conditions 
All reset conditions are supported by MPSIM 
 
A Power-On-Reset can be simulated by using the RS instruction.  all special- 
purpose registers will be initialized to the values specified in the data  
sheet. 
 
A MCLR reset during normal operation or during SLEEP can easily be simulated  
by driving the MCLR pin low (and then high) via the stimulus file, by using  
the SE command, or by using the DK command. 
 
A WDT time-out reset is simulated when the WDT is enabled (see DW command) and  
the proper prescaler is set (see the FW command) and the WDT actually  
overflows.  WDT time-out period is approximated at 12 ms (to closest  
instruction cycle multiple) but can be changed by using the WP command. 
 
The Time out (TO) and Power-Down (PD) bits in the ALUSTA register reflect  
appropriate reset condition.  This feature is useful for simulating various  
power-up and time-out forks in the user code. 
 
Sleep 
MPSIM simulates the SLEEP instruction and will appear asleep until a wake-up  
from sleep condition occurs.  For example, if the Watchdog timer has been  
enabled, it will wake the processor up from sleep when it times out (depending  
on the fuse setting by the FW command).  Another example of a wake-up-from- 
sleep condition, would be an input change on PORT B.  If the interrupt is  
enabled and the GLINTD bit is set, the processor will wake-up and will resume  
executing from the instruction following the SLEEP command.   If the GLINTD =  
0, the normal interrupt response will take place. 
 
WDT 
The Watchdog timer is fully simulated in the MPSIM simulator.  Because it is  
fuse-selectable and fuse-configurable on the device, it must be enabled and  
configured by separate commands (see the DW  and the FW commands) in MPSIM.   
The basic period of the WDT (with prescaler = 1) is approximated at 12ms (to  
closest instruction cycle multiple) but can also be changed via the WP  
command. 
 
Stack 
MPSIM presents an accurate simulation of the hardware stack on the PIC17CXX,  
and additionally provides warning messages if an underflow or overflow  
condition occurs.  When a CALL or LCALL instruction is encountered or when an  
interrupt has occurred, the value of the PC+ 1 is pushed to the stack. The  
stack is popped when a RETLW, RETURN, or RETFIE instruction is executed.  If  
more than sixteen values are pushed to the stack before it is popped, the  
value will be pushed to the stack, a warning message will be issued indicating  
a stack overflow condition, and the STAKAVL bit will be cleared until a reset  
condition occurs   
 
Instruction Set 
The entire 17CXX instruction set is supported, including pre-increment and  
post-increment of indirect-address registers (according to their  
configuration).  The TABLRD and TABLWT instructions are also fully supported,  
including long writes for the TABLWT instruction.  The hardware multiply  
instructions, MULLW and MULLWF are both fully supported as is the MOVLP  
instruction. 
 
Special Registers 
To aid in debugging this device, certain items that are normally not  
observable have been declared as special registers.  Prescalers cannot be  
declared in user code as registers, so there ar special labels that can be  
added to the view screen.  You can add them as you normally would any other  
register declared in your code, specifying any radix to view them. 
The following special item can be added to the view screen when the PIC17C44  
has been selected: 
    T0PRE (Prescaler for Timer 0) 
    WDTPRE (Prescaler for WDT) 
 
Peripherals 
Along with providing core support, the following peripheral modules (in  
addition to general-purpose I/O) are supported: 
   -  Timer 0 in both internal and external clock modes 
   -  Timer1 and Timer2 (and their respective period registers) 
   -  Timer3 
   -  Two Capture Modules 
   -  Two PWM Modules 
   -  USART (limited) 
 
Tcycle Limitation 
It is important to remember that because MPSIM executes on instruction cycle  
boundaries, resolutions below 1Tcy cannot be simulated.  Please see the  
following section for more details concerning the limitations of T-cycle  
simulation. 
 
MPSIM is a discrete-event simulator where all stimuli are evaluated an all  
response generated at instruction boundaries or Tcy.  One Tcy = 4 Tosc (where  
Tosc is input clock).  Therefor, there are several events that can not be  
accurately simulated in MPSIM.  These fall into two categories: 
   -  Purely asynchronous events 
   -  Synchronous events that occur at Tosc clock boundaries 
 
Because of this, the following items are not supported in MPSIM: 
   -  Timer0 prescaler is capable of accepting clock pulse inputs smaller than  
Tcy, but these can not be simulated. 
   -  Capture input pulses can be smaller than one Tcy, but can not be  
simulated. 
   -  PWM output pulse resolution less than 1Tcy is not supported 
   -  In unsynchronized counter mode, clock input smaller than Tcy is not  
supported. 
 
In summary, the net result of instruction boundary simulation is that all  
events get synchronized at instruction boundary and events smaller than one  
instruction cycle get lost. 
 
TIMER0 
Timer0 (and the interrupt it can generate on overflow) is fully supported by  
MPSIM, and will increment by the internal or external clock.  Delay from  
external clock edge to timer increment has also been simulated, as well as the  
interrupt latency period.  Clock input must have a minimum high time of 1Tcy  
and a minimum low time of 1Tcy due to the stimulus file requirements.  The  
prescaler for Timer0 is made accessible as T0PRE.  It can be watched and  
modified. 
 
TIMER1 and TIMER2 
Timer1 and Timer2 in its various modes is fully supported by MPSIM.  Delays  
from clock edge to increment (when configured to increment from rising or  
falling edge of external clock) is simulated as well as the interrupt latency  
periods. Clock input must have a minimum high time of 1Tcy and a minimum low  
time of 1Tcy due to the stimulus file requirements. 
 
TIMER3 and Capture 
MPSIM fully supports Timer3 and the Capture module in all of its modes.   
Delays from clock edge to increment (when configured in external mode), delay  
for capture and interrupt latency periods are fully supported. Clock input  
must have a minimum high time of 1Tcy and a minimum low time of 1Tcy due to  
the stimulus file requirements. 
 
PWM 
Both PWM outputs are supported (resolution greater than 1Tcy only) are  
supported in this version of MPSIM. 
 
USART 
Timing and interrupt generation is supported.  Baud rate generator is  
supported.  Reading and writing of the registers are supported but actual  
receive or transmit operation is not simulated. 
 
Memory Modes 
The following memory modes are supported by MPSIM: 
   -  Microcontroller Mode 
   -  Extended Microcontroller Mode 
   -  Microprocessor Mode 
 
The default is Microcontroller mode, which has 8K of program-memory on-chip.   
If you would like to use any of the other modes, you must use the FW command  
(since this option is fuse-selectable on chip).   

