Other Parts Discussed in Thread: MSP430F6736A
Hello!
I am using CCS6.0.1 and the TI C compiler version 4.4.1. I think I am seeing a mismatch between the data memory model I select in the project properties in CCS, and what is used (or at least reported) by the TI assembler. I am not 100% sure if this is causing different code generation, or maybe the assembler is printing the wrong thing at the top of the .asm file. Possibly it's not a bug at all, and the options seen in Eclipse don't map 1:1 with what is in the .asm file.
The question: Should I expect the .asm file to report the same data memory model I selected in Eclipse?
The quick version: If I compile the "Blink the LED" sample code for an MSP430F6736A, I see the following:
What I set in Eclipse / what appears on the console during build / what is reported in .asm file:
restricted / restricted / large
small / small / large
large / large / huge
blank / blank / small
What I think should be different: The memory model reported in the .asm file and the one I select in Eclipse should be the same.
If the compiler, assembler, or linker has the ability to detect that the project won't being compiled won't fit in the selected model, or is otherwise not suitable, it might be OK to automatically use a bigger/different one, but there should be a diagnostic message in case this happens. The project I am testing with is very small, so I don't know what happens in this case.
Why I care:
I care about this because in my actual project, I think I need to use the large data memory model. I was trying to set this up in Eclipse, but I wasn't always getting the results I expected when I tried to run the code for my actual project. When looking at the .asm files, I noticed that what I set in Eclipse and what was at the top of the .asm didn't match. This may not be the problem I am actually having with my project, but it at least seems odd to me.
Steps to reproduce:
1. Start with a PC that has never had CCS on it before. This may not be a hard requirement, but it was what I did.
2. Download the offline installer of CCS 6.0.1.00040 from http://processors.wiki.ti.com/index.php/Download_CCS#Code_Composer_Studio_Version_6_Downloads and install it.
3. Use the update feature within CCS to get the latest TI C compiler, version 4.4.1.
4. Start a new CCS project. Pick your MSP430 flavor (I picked MSP430F6736A, as that's what I have.) Use the TI C compiler. Select the "Basic Examples > Blink The LED" from the "Project templates and examples" box.
5. Right click on the project in Project Explorer and select Properties. Under CCS Build > MSP430 Compiler > Advanced Options > Assembler Options, check both the "Keep the generated assembly language (.asm) file" and the "Generate listing file" boxes.
6. Under CCS Build > MSP430 Compiler > Processor Options, observe that the data memory model is set to restricted by default.
7. Hit OK to close the project properties.
8. From the Project menu, select Build All.
9. Look at the console window. Both the compiler and the linker will have --data_model=restricted in their command lines. This is what I expect.
10. Open up the .asm file (in Eclipse or your favorite text editor). The .compiler directive near the top will have --mem_model:data=large in it. This is not what I expect; I expect it to be restricted.
11. Back in Eclipse, right click on the project in Project Explorer, select Properties, go to CCS Build > MSP430 Compiler > Processor Options, set the data memory model to small, and click OK.
12. From the Project menu, select Build All.
13. Look at the console window. Both the compiler and the linker will have --data_model=small in their command lines. This is what I expect.
14. Open up the .asm file (in Eclipse or your favorite text editor). The .compiler directive near the top will have --mem_model:data=large in it. This is not what I expect; I expect it to be small.
15. Repeat steps 11-13, setting large in Eclipse. The console will show --data_model=large (as expected), but the .asm file will show --mem_model:data=huge (expected =large).
15. Repeat steps 11-13, setting blank (nothing selected) in Eclipse - you may have to select this twice before the dropbox will stay blank. The console will show no --data_model option to either the compiler or linker (probably OK). The .asm file will show --mem_model:data=small . I am not sure if "small" is OK, or if the .asm should show no compiler option at all.
Hardware details:
I am running CCS on Windows 7 Pro, SP1, 64-bit. My connection to the target is via a TI MSP-FET430UIF, using SPY-BI-WIRE to the /RST and TEST pins on the MSP430.
Other notes:
The latest MSP430 C compiler manual (SLAU132J, http://www.ti.com/lit/ug/slau132j/slau132j.pdf ) only talks about small, large, and restricted memory models. "Huge" isn't mentioned.
If they would help, I have the console output and .asm files from trying to compile with different settings for the data_memory_model. I may need to scrub a directory name out of them but I can provide them if needed.
Thanks!
Matt Roberds
(edit: corrected MSP part number and tags)
