Change stack address during runtime

Truong Nguyen Xuan78

Prodigy 130 points

Other Parts Discussed in Thread: TMS320F28069

Dear Experts,

Is there anyway to set the stack to another address in SRAM.

Truly, I want to change the SP to specific memory region that differ with current address that SP points to.

Regards,

Fitz

over 9 years ago

0 Christopher Chiarella over 9 years ago

TI__Mastermind 30255 points

Fitz,

You can edit the linker command file and re-assign the .stack section to a different RAM section.
processors.wiki.ti.com/.../C28x_Compiler_-_Understanding_Linking

Best Regards
Chris

0 Truong Nguyen Xuan78 over 9 years ago in reply to Christopher Chiarella

Prodigy 130 points

Thank for your answer Christopher.

I've already changed the address of .stack section to larger space in SRAM (RAML4).
But this change is static.
I would change the SP during the run time after saving it into some where.
I'm using TMS320F28069.

I tried to do that with ASM code like this:
__asm(" MOV AR0, SP")
__asm(" MOV SP, AR1")
But when I compile that code, assembler gave me an error: illegal combination.

So, could you please share how to change SP during the run time with TMS320F28069?

Thank you so much for your support.
Regards,
Fitz

0 Truong Nguyen Xuan78 over 9 years ago in reply to Truong Nguyen Xuan78

Prodigy 130 points

BTW, Christopher,
I changed to write asm file to save current value of SP instead of C-callable and the issue came at this LOC:

MOVL XAR1,*XAR0
MOVL XAR2,*XAR1
MOV AR0,SP -> [E0004]
Illegal operand combination
MOV AR0,SP
Is this the issue of TI's assembler?

Regards,
Fitz

0 Christopher Chiarella over 9 years ago in reply to Truong Nguyen Xuan78

TI__Mastermind 30255 points

Fitz,

Moving the SP to an auxiliary register isn't supported in the architecture. You can move the SP to the accumulator and then move that value into an auxiliary register. You can set the SP from an auxiliary register though.

MOV AL, SP ;Save stack pointer address to accumulator
MOV AR1, AL ;Move accumulator value into AR1
MOV SP, AR0 ;Move a new address value from AR0 to SP

Best Regards
Chris

0 Truong Nguyen Xuan78 over 9 years ago in reply to Christopher Chiarella

Prodigy 130 points

Hi Christopher,

Nice. It's working now.
Thank you so much for your supporting.

Regards
Fitz

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Change stack address during runtime