HCS12 Hardware and Software Development Tools. The HCS12 Microcontroller

Transcription

1 HCS12 Hardware and Software Development Tools The HCS12 Microcontroller

2 Development Tools Software Development Tools Text editor: for entering source code using a PC Terminal program: allows a PC to communicate with the demo board Cross assembler: running on a PC to assemble programs written in an assembly language Cross compiler: running on a PC to compile programs written in a high-level language Simulator: running on a PC and allows to user to verify the logic of user programs Source-level debugger: running on a PC and allows the user to verify programs by using breakpoints, watch list, run-to-cursor, and so options to verify the correctness of programs Integrated development environment (IDE): a software running on the PC that combines a text editor, terminal program, cross assembler, cross compiler, and source-debugger and allows the user to switch from one tool to another without quitting any of them.

3 Software Tools Used in this Book MiniIDE: consisting of a text editor, a cross assembler, a terminal program, and a simple project manager (a freeware) asmide: consisting of a text editor, a cross assembler, a terminal program, and a simple project manager (a freeware) ICC12: consisting of a text editor, a cross C compiler, a terminal program, and a simple project manager (demo version of ImageCraft product 8 kb size limit) CodeWarrior: consisting of a text editor, a cross assembler, a cross C compiler, driver programs for serial monitor and several BDM adaptors, and a source-level debugger (demo version of Freescale product 32 kb size limit) EGNU and GNU C compiler: consisting of a text editor, a C compiler, a terminal program, and a simple project manager (a freeware)

4 Hardware Development Tools BDM-based Debug Adapter The HCS12 provides a background debug module that allows the user to perform software debug activities (set break-point, trace program, execute program to a breakpoint or a certain location, etc) via the serial interface. In-Circuit Emulator (ICE) ICE is an expensive hardware that allows the developer to perform program debug activities before their hardware has been constructed. Demo Board A demo board allows the user to test their programs using the target microcontroller before their final hardware has been constructed. Digital or ordinal Oscilloscope A oscilloscope allows the user to observe the waveform generated from the microcontroller And hence enables the user to verify their program logic. Only demo boards will be discussed.

5 Types of Demo Boards Demo Boards with the D-Bug12 Monitor Wytec Dragon12-Plus Wytec Mini-Dragon Demo Boards with the Serial Monitor Wytec Dragon12-Plus Wytec Mini-Dragon Demo Boards with the BDM Adaptor Freescale Project boards with a HCS12DT256 module and a P&E BDM interface Axiom Manufacturing CMD-12DP512 with the Turbo BDM Light (TBDML) interface

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7 The Dragon12-Plus Demo Board - 24 MHz bus speed (generated from a 4-MHz crystal). - D-Bug12 or serial monitor - 16 x 2 LCD kit (4-bit interface) - Eight LEDs - Four seven-segment displays - Keypad connector - Four buttons for input - DIP switches for input - Buzzer for playing siren and songs (wired to the PT5 pin) - Potentiometer for testing A/D function (wired to PAD7 pin) - Infrared transceiver - CAN transceiver (Philips PCA82C250) - A small breadboard - BDM IN and BDM OUT connectors - Two RS232 connector - LTC bit D/A converter chip with SPI interface - 24LC16 serial EEPROM with I 2 C interface - A DIP switch - A Temperature sensor

8 The Mini-Dragon Demo Board

9 The D-Bug12 Monitor - Supports most HCS12 devices with 128KB and 256 KB flash memory - Used in many demo boards - Requires a host terminal program that supports the Xon/Xoff software handshake for proper operation - The HyperTerminal bundled with Windows and the terminal program bundled with asmide, miniide, ICC12, and EGNU IDE can work with D-Bug12 monitor - Supports four operating modes: EVB mode, Jump to EEPROM mode, POD mode, and Serial Bootloader mode - After reset, the D-Bug12 reads the logic levels on the PAD1 and PAD0 pins to decide which of the four D-Bug12 modes to enter.

10 EVB Mode - The D-Bug12 monitor operates from the flash memory - The users are restricted to use SRAM (from $1000 to $3BFF) or EEPROM to run application programs. - The user runs a terminal program on the PC to communicate with the D-Bug12 monitor on the demo board. - EVB operation model is shown in Figure When the demo board is powered up and the baud rate is set properly, the message as shown in Figure 3.5 will appear on the terminal screen. D-Bug b24 Copyright Motorola Semiconductor For Commands type "Help" > Figure 3.5 D-Bug12 EVB mode sign on message

11 - The D-Bug12 monitor displays the > character to indicate it is ready for operation. - When a command issued to D-Bug12 is successfully executed, the monitor displays the execution result and a new > character on a new line. - If a command is not successfully executed, one can press the reset button to get out. - An alternative to get out of the unsuccessful command is to press the abort key. - The abort key is connected to the XIRQ signal. - The Dragon12-Plus demo board uses the MC9S12DG256 as their MCU. - The memory maps for these two demo boards are shown in Table 3.2.

12 Using CodeWarrior Has a built-in simulator. Supports debugging using the serial monitor resident on the demo board. Has drivers with several BDM-based debug adapters: 1. P&E Multilink/CyclonePro BDM adaptor 2. TBDML adaptor 3. Abatron BDI adaptor 4. Softec s indart debugger

13 Building a Software Project Using CodeWarrior CodeWarrior is started by clicking on its icon. The startup screen is shown in Figure The user can read a few tips of the day and then leave the tip of the day by clicking Close.

14 Project Setup Step 1 Create a new project by pressing the File menu and select New. A popup dialog box will appear to allow you to enter the project name as shown in Figure Step 2 Enter the project name and the project directory and then click on OK. The screen will change to that in Figure Step 3 Select the HCS12 device (MC9S12DG256 for Dragon12-Plus) and the click on Next. Step 4 Select the set of languages to be supported initially. Choose assembly for this tutorial and then click on Next. Step 5 Select absolute or relocatable assembly. Choose absolute assembly for this example and Then click on Next. Step 6 Choose the connection method to the target hardware. Choosing multiple connection allows the user to switch to among several connection methods. The screen in Figure 3.27 Selects 3 connection methods. Click on Finish to complete the project setup. The resultant Screen is in Figure 3.28.

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16 Source Code Entering During the project creation process, CodeWarrior also creates the required files for the project and put them under different directory names (Sources, Prm, Libraries, Debugger Project File, and Debugger Cmd Files). The user can display the file names under these directories by clicking on the + character to their left. Figure 3.30 shows the files created under these directories.

17 Two Methods for Entering a Program 1. Modify the main.asm program 2. Enter the program with a different name and add it to the project

18 Example Program include "c:\cwhcs12\include\hcs12.inc" ARCNT equ 20 org $1000 sum ds.w 1 average ds.w 1 icnt ds.b 1 org $1500 start movw #0,sum movb #ARCNT,icnt ; initialize loop count ldx #array ; use X as a pointer to the array addloop ldd sum ; add array[i] to sum and move pointer addd 2,x+ ; std sum ; dec icnt ; decrement loop count bne addloop ; not done yet? ldd sum ; compute array average by dividing array count into ldx #ARCNT ; array sum idiv ; stx average ; save the average bra $ ; stay here forever array dc.w 11,12,13,14,15,16,17,18,19,20 dc.w 21,22,23,24,25,26,27,28,29,30 org $FFFE ; set up reset vector dc.w start end

19 Open the main.asm program (by double clicking on its name) and replace it with the program in the previous page and save it. CodeWarrior requires Reset vector setup org $FFFE dc.w start

20 Deleting a File from a Project Press right mouse button on the name of the file to be deleted and select Remove as shown in Figure 3.31 Adding a File into a Project Press the right mouse button on Sources and select the file name from the directory that contains the file.

21 Project Build A project can be built by pressing Project menu and selecting Make or pressing the F7 function key on the keyboard. Nothing will be displayed when the project has no error. A project with errors will be displayed as shown in Figure 3.33.

22 Program Debugging This phase is entered by pressing the function key F5 or selecting Debug from the Project menu. The initial response of CodeWarrior depends on the chosen connection method. Initial Response under Serial Monitor When CodeWarrior works with a demo board with a resident Serial monitor, the response is shown in Figure After clicking on OK, the screen changes to Figure Pressing the reset button in Figure 3.35 and the screen will change to that in Figure Initial Response under P&E Multilink (Freescale Project Board) The initial response after pressing the F5 function is shown in Figure After pressing the OK button, the screen changes to that I n Figure 3.37.

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27 Debugger Screen Layout Source window. Source code is displayed. Data window. All program variables are displayed in this window. Command window. The user can enter debugging commands in this window. Assembly window. Assembly instructions with line numbers to their left are displayed. Register window. The value of each CPU register is displayed here. Procedure window. All program procedures are displayed here. Memory window. This window displays every memory location in the hardware.

28 An Example of a CodeWarrior Debug Session 1. Single step over a few instructions. Click on the Step over button once. The value of sum in the data changes to 0. Click on the Step over button one more time. The value of icnt is changed to 20. Click on the Step over button one more time. The value of the index register X is changed to $1529. After executing the first three instructions, the screen is changed to Figure Execute Run to Cursor Command. Use this command to find out the execution result up to a certain instruction. Press the right mouse button on the bne addloop instruction and select the Run to Cursor command as shown in Figure After this, the value of sum is changed to 11 and the value of icnt is changed to 19. Next, move the mouse button to the ldd sum instruction and the value of sum is changed to 410 and is correct. Move the mouse cursor to the next instruction (bra $) and press run to cursor again. This time the variable average is changed to 20 and is correct.

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