User`s guide

MPLAB

IDE User’s Guide

If the code did not assemble and link successfully, check the following items and then

build the project again:

• If the assembler reported errors in the Output window, double click on the error

and MPLAB IDE will open the corresponding line in the source code with a green

arrow in the left margin of the source code window.

• Check the spelling and format of the code entered in the editor window. Make sure

the new variables and the special function registers, TRISC and PORTC, are in

upper case.

• Check that the correct assembler (MPASM assembler) and linker for PICmicro

MCU devices is being used. Select Project>Set Language Tool Locations

. Click

on the plus boxes to expand the Microchip MPASM toolsuite and its executables.

Click MPASM Assembler (mpasmwin.exe) and review their location in the dis-

play. If the location is correct, click Cancel. If it is not, change it and then click OK.

The default search paths can be empty.

Upon a successful build, the output file generated by the language tool will be loaded.

This file contains the object code that can be programmed into a PICmicro MCU and

debugging information so that source code can be debugged and source variables can

be viewed symbolically in Watch windows.

2.12 TESTING CODE WITH THE SIMULATOR

In order to test the code, software or hardware is needed that will execute the PICmicro

MCU instructions. A debug execution tool is a hardware or software tool that is used to

inspect code as it executes a program (in this case cnt8722.asm). Hardware tools

such as MPLAB ICE or MPLAB ICD 2 can execute code in real devices. If hardware is

not available, the MPLAB SIM simulator can be used to test the code. For this tutorial

use MPLAB SIM simulator.

The simulator is a software program that runs on the PC to simulate the instructions of

the PICmicro MCU. It does not run in “real time,” since the simulator program is

dependent upon the speed of the PC, the complexity of the code, overhead from the

operating system and how many other tasks are running. However, the simulator

accurately measures the time it would take to execute the code if it were operating in

real time in an application.

Note: The real power of projects is evident when there are many files to be

compiled/assembled and linked to form the final executable application –

as in a real application. Projects keep track of all of this. Build options can

be set for each file that access other features of the language tools, such

as report outputs and compiler optimizations.

Note: Other debug execution tools include MPLAB ICE 2000, MPLAB ICE 4000

and MPLAB ICD 2. These are optional hardware tools to test code on the

application PC board. Most of the MPLAB IDE debugging operations are

the same as the simulator but, unlike the simulator, these tools allow the

target PICmicro MCU to run at full speed in the actual target application.