8-bit MicrocontrollersのトピックMC68HC908JB16 Codewarrior question

MC68HC908JB16 Codewarrior question

mo — Wed, 05 Apr 2006 06:25:31 GMT

Hi all,
So I am using the MC68HC908JB16JDW via a USB connection and it allows ICP. But I'm not used to using Codewarrior and I need to know how to memory map my C code that I write in Codewarrior to a proper memory location, so that it doesnt overwrite the ICP determination code which I must install in a separate write operation.
Is it even possible to make sure that the code you write goes to a specific memory location or at least redirect the vectors so that the vectors points to the right location.
Any help would be appreciated. I posted earlier in the 16 bit section, but Peg recommended to move to 8 bit section.
Thanks all.
Mo

Re: MC68HC908JB16 Codewarrior question

Blackwolf — Wed, 05 Apr 2006 18:39:42 GMT

Hello Mo,

yep, absolutely...

you can map your application at any location you want. Please check out the chapter dealing with 'Pragmas' in the compiler manual.

Here is a small (simple, basic and rough) example:

Subject: let's place the function dummy() at addres 0xC000 and main() as well as dummy2() at 0xD000

In your C file:

#pragma CODE_SEG MYCODE

void dummy()

{

...

}

#pragma CODE_SEG DEFAULT

void main ()

{

...

}

void dummy2()

{

...

}

In your PRM file:

SECTIONS
...
   MY_CODE          = READ_ONLY 0xC000 TO 0xCFFF;
   OTHER_CODE = READ_ONLY 0xD000 TO 0xFFFF;
...
END

PLACEMENT
...
DEFAULT_ROM             INTO OTHER_CODE;
MYCODE                        INTO MY_CODE;
...
END

There are some more detailed examples of PRM files in the linker manual, but that's basically the way it should work

Blackwolf

Re: MC68HC908JB16 Codewarrior question

mo — Wed, 05 Apr 2006 21:43:05 GMT

cool thanks blackwolf