Erase segment problem in msp430f5418A

Jino Sebastian said:

I have enabled large data model and large memory model. So I assume that I should be getting 20 bit addresses.

The compiler first evaluates the expression and then casts it to the target type. The evaluation of constants is IMHO 16 bit by default unless you explicitely tell that it isn't.

For the same reason, (segNo*FLASH_SEG_SIZE) will return an int, even if segNo should be >128.

Add an "L" or "UL" size identifier to the constants and try again.

Thanks Jens for your suggestion.

I tried this but still no luck. I have seen one of your posts regarding a similar issue and tried far pointer [char far *] but this also does not solve my issue.

I will try with TI example code and see if I can get this to work.

Regards,

Jino

Jino Sebastian said:

I tried this but still no luck.

It's the (SegNo*FLASH_SEG_SIZE) expression that 'fails'. SegNo is an unsigned int, but FLASH_SEG_SIZE is a signed int (uless explicitedly declared to be unsigned).
As a result., it looks like you get an signed int overflow, and what should be 0x8000 turns into -32768. which as result looks like 0x10000 is missing.

Try declaring FLASH_SEG_SIZE explicitely as long

Hi Jens,

I have tried this setting as well but still this fails.

I have tried this same code without sys/bios and it started working.

With sys/bios, however it fails. When I checked the sys/bios makefile src->Sysbios->Makefile the data model is specified as "restricted" eventhough project ->properties is specified as large.

So it seems that sys/bios is overriding my Global settings.

Searching for solution, I see this post

http://e2e.ti.com/support/microcontrollers/msp430/f/166/t/258699.aspx

Jino Sebastian said:

With sys/bios, however it fails. When I checked the sys/bios makefile src->Sysbios->Makefile the data model is specified as "restricted" even though project ->properties is specified as large.

You didn't mention you're running your code under SYS/BIOS. (Edit: you did, I just didn't see) Well I hadn't made a differene as I'm not familiar with it. I have my own colleciton of OS-like code (including a multitasker)

It is possible that SYS/BIOS overrides large code model because this specific version doesn't work with large data model. Large data model has a serious impact on many aspects. Most of them can be handled by the compiler, but I guess that SYS/BIOS contains some assembly code as well, especially the task switching code, and this code needs to be significantly different for large data model.

The workaround is what I have done soem tiem ago when there was no support for large data model in MSPGCC: write a dedicated function that takes a long argument, and passes it to some inline assembly code that generates the necessary 20 bit reads and writes.
I think that IAR and maybe even CCS has some intrinsics that take a 32 bit argument and perform a 20 bit read or write of a byte or word, wrapped with blocked interrupts, so suitable for flash operation too.

Thso intrinsics will then just repalce your data pointer access and the compielr generates the necessary code.

Hi Jens,

"You didn't mention you're running your code under SYS/BIOS".

Yes I did in the original post, even though I didn't expect the issue would be with the OS. ("I am using sys/bios, but I suppose it is no way related to that.")

"The workaround is what I have done soem tiem ago when there was no support for large data model in MSPGCC: write a dedicated function that takes a long argument, and passes it to some inline assembly code that generates the necessary 20 bit reads and writes. "

Thank you for the suggestion. I will try it, but may be a little time consuming since I am not familiar to assembly programming of MSP430

Thanks,

Jino