Code%20Composer

1
Code Composer
ECE 2560

• Department of Electrical and
• Computer Engineering
• The Ohio State University

2
The Code Composer

• Code Composer
• An interactive compiler, assembler, debug system
  for development of programs for the MSP 430.
• Developing an assembler program in Code Composer
• Demo of a simple program

3
Documentation

• You can bring up help in CCS
• Brings up a new window
• You can do a search on assembler language or 430
  Compiler Users Guide
• Click at top of page on Compiler Version x.x
  Users Guide
• Will allow you to navigate to assembler Language
  tools users guide
• In 1.1 is the diagram

4
A top level view

• Where assembler language fits
• As the assembler is part of a code development
  system it is more sophisticated than typical
  assemblers.

5
CCS assembler

• Using code composer for assembler
• Launch CCS
• Select New Project
• Give the project a name
• End name with .asm
• Output type leave as Executable
• Choose a location by unclicking use default and
  select your directory

6
CCS starting project (2)

• In the device area
• Choose the MSP 430 for Family
• Most likely this is the only option
• Variant Leave 1st box blank
• Variant 2nd Box should be MSP430G2553
• This is the 430 that is on the launchpad
• As we will be using the debugger this is very
  important
• Should be USB1 the default

7
Under Advanced

• You need to have the correct linker command file
  
• Here lnk_msp430g2553
• When selected click OPEN

8
Under Project Templates

• Choose Empty Assembler-only Project
• Click on Finish

9
The first window for project

• Have several areas
• Project
• Coding
• Problems

10
Some first code

• For first coding load values into some registers
• 0004 into R4
• F012 into R5
• 0066 into R6

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The project name

• Rename main.asm
• Go to the Project Explorer Window
• Expand it and you will see main.asm
• Right click, choose rename and do a rename
• You will see the new_name.asm at the top of the
  coding window now.
• BE SURE YOU HAVE .asm extension

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The coding window

• Time to enter code
• Discussion of code sections
• Entering code - get some free lines first
• END CODE WITH INSTRUCTION
• Loop JMP Loop
• This is so the program ends. This instruction is
  called an endless loop.

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First Instructions

• Assembler instruction format
• Label Instr op1,op2 comment
• They are
• MOV 0x0004,R4 comment
• MOV 0xF012,R5 note sign
• MOV 0x0060,R6 note hex representation
• MOV R4,R7
• Enter and compile

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Chip demo

• Now compile and download to chip
• Connect the launchpad
• Choose DEBUG under RUN selection
• New window format appears

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Run code

• Can run code to end or step instruction by
  instruction
• STEP can be done by using F5 as seen in RUN menu
• Also want to watch registers
• Expand the core registers listing
• NOTE window is CCS Debug also have the CCS
  Edit which may be hidden

16
Watch the action

• Can see PC incrementing
• Can see SP being set
• Can see values loaded into registers

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So what is this showing use

• When executing
• To restart your code you can do a hard reset
• The initial instructions
• CLR Rx - clears register x to 0s
• Register Mode
• MOV 0xFOO4,R4
• Immediate addressing mode
• MOV 0x0060,R6
• Another immediate addressing mode instruction
• Note way in which hexadecimal is specified

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More on addressing

• MOV R4,R7
• Register mode Copies the value in R4 to R7 so
  they have the same value
• MOV R7,buf
• Move the contents of R7 to the address indicated
  by buf. buf is user defined symbol and has a
  value (next slide)
• What is the value of buf
• MOV buf,R6 shows what the value of buf is
• Note that buf has a value of 200
• And that value is in R6

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Data/variables for your progam

• Where is buf?
• To set up the area for variables/constants
• After your code, i.e., after Loop JMP Loop
• Start line .data
• buf .word 0
• vals .byte 14,3,12

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The other addressing modes

• Indirect Register Mode
• Example MOV _at_R6,R4
• Note that the address of buf is 0200 and it has
  been loaded into register R6
• The memory location at address buf has contents
  F004
• Note R4 after execution

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Indexed mode addressing

• First clear the registers
• Memory was set up as follows
• Address lbl contents
• 0234h d1 0011h
• 0022h
• 0238h d2 0033h
• 0044h
• 023Ch d3 0055h
• 0066h

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Indexed addressing mode

• MOV 2(R4),R6
• This should move the contents of the word stored
  at 2 past the value in R4
• R4 contains value 0234h which labeled d1
• At memory address 0234h 0011h
• At memory address 0236h 0022h
• So instruction should move 0022h to R6

23
Indirect autoincrement

• Do some loading of R7 using R4 with
  autoincrement.
• MOV _at_R4,R7
• Can watch this in emulation on a chip

24
Summary - Assignment

• Saw an initial demo of how to use CCS
• A look ahead
• Will cover some basics on instructions - Like
• What is the instruction to load a value of 7h
  into R8?
• Write the instruction to add R4 to R9 with the
  result going to R9.
• HW 2 is on the webpage