topic Re: 16-bit stack on HC908 CodeWarrior in CodeWarrior for MCU

16-bit stack on HC908 CodeWarrior

antgalimbe — Thu, 01 Jun 2006 13:41:32 GMT

I have tried to move the stack pointer in a Tiny program outside the zero-page memory but I have discovered that the program crash.
I see the disasseble of the C-code and I discovered that the C-compiler of Codewarrior assume the stack in zero-page.
Is possible to tell to the compiler to assume the stack outside the zero-page?
The actual project run on HC908JL8.

Re: 16-bit stack on HC908 CodeWarrior

CrasyCat — Thu, 01 Jun 2006 15:48:42 GMT

Hello

According to the HC08 compiler manual "In the TINY memory model, all data including stack must fit into the zero page."

This is the definition of the memory model and cannot be changed.

CrasyCat

Re: 16-bit stack on HC908 CodeWarrior

antgalimbe — Thu, 01 Jun 2006 15:54:50 GMT

Thanks for your answer. My hope was to find an option to allow only the stack outside the zero-page and not all the data.

Re: 16-bit stack on HC908 CodeWarrior

CompilerGuru — Fri, 02 Jun 2006 18:34:25 GMT

The memory model only defines the default way how data are allocated.
If you want the stack to be outside the zero page, I would suggest to use the small memory model. With this, normal, non qualified pointers will be 16 bit and they can therefore point to objects on the stack.
Then place your globals explicitely into a section in the zero page
Put a

#pragma DATA_SEG SHORT _DATA_ZEROPAGE

before the declaration and before the definition of them, and terminate the area with a

#pragma DATA_SEG DEFAULT

PS: To switch the memory model, you have to adapt the compiler/assembler memory model option and to pick the right library. Create a project witht the new project wizard to get a sample, if needed.

Daniel