1. Code Composer Department of Electrical and Computer Engineering
ECE 2560
Code Composer
Department of Electrical and
Computer Engineering
The Ohio State University
ECE Lecture 1

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
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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 User’s Guide
Will allow you to navigate to assembler Language tools users guide
In 1.1 is the diagram
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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.
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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
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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
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7. Under Advanced You need to have the correct linker command file –
Here : lnk_msp430g2553
When selected – click OPEN
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8. Under Project Templates
Choose Empty Assembler-only Project
Click on Finish
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9. The first window for project
Have several areas
Project
Coding
Problems
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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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11. 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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12. 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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13. First Instructions Assembler instruction format
Label: Instr op1,op2 ;comment
They are
MOV #0x0004,R ;comment
MOV #0xF012,R ;note # sign
MOV #0x0060,R ;note hex representation
MOV R4,R7
Enter and compile
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14. Chip demo Now compile and download to chip Connect the launchpad
Choose DEBUG under RUN selection
New window format appears
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15. 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
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16. Watch the action Can see PC incrementing Can see SP being set
Can see values loaded into registers
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17. 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 0’s
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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18. More on addressing MOV R4,R7 MOV R7,&buf What is the value of buf
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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19. 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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20. The other addressing modes
Indirect Register Mode
Example MOV @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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21. 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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22. 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 h
At memory address 0236h h
So instruction should move 0022h to R6
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23. Indirect autoincrement
Do some loading of R7 using R4 with autoincrement.
Can watch this in emulation on a chip
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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
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