CP316: Microprocessor Systems and Interfacing

Introduction to the Development Environment (Simulator)

Objectives

Development Kits are small prototyping boards typically obtained from the microprocessor/microcontroller manufacturer. Software is developed on a microcomputer, assembled, simulated and tested, and then downloaded to the target system (development board).

1. introduce the QwikFlash Development Board
2. test the QwikFlash board using the pre-programmed performance verification program
3. introduce the MPLABX IDE
4. introduce the MPLABX IDE simulator

Equipment

• QwikFlash Development Board pre-programmed with the performance verification program
• development board power supply
• microcomputer with MPLABX IDE installed

Procedure

1. Take the QwikFlash development board and it's power supply from the hardware kit.
   
   
2. Test the board using the pre-programmed performance verification program. Follow the procedure in QwikFlash Board Test .
   
   The board test provides a simple way of testing most components on the board. At any point during the term, if you think there are problems with your board, use this program to test your board.
   
   Demonstrate the board test to the lab supervisor.
   
   
3. Put away the hardware and lock up your cabinet.
   
   
4. To program the board, you will use the MPLABX IDE to enter assembly code, build and assemble your project, then test your code with the built-in simulator. Today you will enter a very short assembly language program, create a project, add the source code to the project, build and test the code.
   
   To use the simulator, follow these instructions:
   Stop the debugger if you have it running, and open the Project Properties menu. Select the simulator instead of the ICD3.
   
   
   Once you've chosen the simulator, you can set the oscillator frequency to 10 MHz to match your board.
   
   
5. Take the program test.asm , create a project, assemble and run.
   
   Notes:
   • When entering code, if the tab spacing is not correct, use Edit > Properties > Sizes  to get an appropriate spacing.
   Demonstrate your familiarity with the IDE to the lab supervisor.
   
   
   
6. Every PIC processor has a set of device configuration bits that are set only once when the device is programmed. To introduce you to the concept of device configuration bits, you will watch a Device Configuration eLearning session from Microchip that was originally done for a different type of 8-bit PIC chip. Although a few of the details are different from our processor, it is still relevant at the concept level.
   • Watch the eLearning session Device Configuration.
   
   
   
7. Device configuration bits can be defined in a number of ways:
   • Device configuration bits can be set in the IDE after selecting the device. How would you set the device configuration bits using the IDE?
   • Although the device configuration bits can be set in the IDE, good programming practice uses directives to set the bits at the start of the program so that the configuration is always downloaded with the program. This practice makes clear your configuration expectations to anyone reading the program.
     • The User's Guide below shows how to use the new, more readable, CONFIG format for setting the device configuration bits.
     • However, you may encounter code that uses the older __CONFIG format.
   • You should always use the new CONFIG format for your code as the older format will cause warnings in newer versions of MPLAB.
   • You cannot mix the CONFIG and __CONFIG directive formats in the same program.
     
     Take your existing program test.asm , modify the device configuration statements to the new style in your existing project, assemble and run.
     
     NOTE: assembly programs are named filename.asm but they will be stored as filename.txt for readability from this web server.
     
     Use one of the following resources:
   • PIC18F452 section from PIC18 Configuration Settings Addendum   [pdf, 350pp; ©2005 Microchip Technology Inc.] describes the new CONFIG assembler directives.
     
   • Part 1, chapter 4, sections 4.11 and 4.12, in the MPASM™ Assembler, MPLINK™ Object Linker, MPLIB™ Object Librarian User's Guide [pdf, © Microchip Technology Inc.] describe the original  __CONFIG format and the new CONFIG assembler directives, respectively.
     
     

Demonstrate your configuration changes and the results of the program to the lab supervisor.