topic MC908GZ60 running LED in 8-bit Microcontrollers

MC908GZ60 running LED

Josef — Tue, 31 Oct 2006 00:11:25 GMT

Hello,

I use the MC908GZ60 and CodeWarrior. I want to programm a simple running LED on Port A in C language.

I wrote a code like this:

char var1 = 0b00000001;

for(; {

asm("rol var1");

PTA = var1;

wait(); // function with loops for time delay

}

When I "make" the project i get following error message:

Error : C18700: Unknown Opcode Operand Combination: Opc.:ROL/Dest.:Ext/Source:NoOp.

main.c line 90

Error : C18701: Unknown Opcode 19

main.c line 90

Error : Compile failed

Can anyone tell me what is wrong with my code?

Thanks for your help!

sincerly yours

Josef

Re: MC908GZ60 running LED

CompilerGuru — Tue, 31 Oct 2006 07:48:46 GMT

your var1 variable has an extended (16 bit) address, but rol only works with direct (8 bit) addresses.
So you either allocate var1 in direct memory:
#pragma DATA_SEG SHORT MY_ZEROPAGE
char var1 = 0b00000001;

or you change your code which does the rotate, for example to a load/rola/store
asm {
lda var1;
rola;
sta var1;
}

Daniel

Re: MC908GZ60 running LED

Josef — Tue, 31 Oct 2006 17:00:09 GMT

Aha, yes with the new code it works.

Thank you for your quick answer!

One further little question. Do you know any good documentation for programming HC08 cores?

Which contains informations about the #pragma, interrupts, ... perhaps with little code examples.

The Help menu of CodeWarrior explains only how to define interrup service routines with the processor expert and the descriptions in the Data Sheet are even less

Josef