Hi,
I'm reposting this from 2006-11-30 because
no one replied then. I've confirmed the issue
still exists with V7.05 beta0.
The compiler-generated interrupt handler wrapper
code preserves R8 and R9 as well as R10~15.
I don't think it should.
From "Assembly Interface and Calling
Conventions" in the online help:
----------------------------------------
Preserved Registers R4~9
These registers are called preserved registers,
since their contents are unchanged by a function
call. Local variables are assigned to these registers
by the compiler.
Volatile Registers R10~15
Can be used in a function without being saved or
restored. These registers are called volatile registers,
since their contents may be changed by a function
call.
Interrupt Handlers
If you write a handler in assembly and if it calls
normal C functions, then the assembly handler
must save and restore the volatile registers,
since normal C functions do not preserve them.
----------------------------------------
I wrote my own wrapper in assembler, which
does not preserve R8 and R9, and everything
seemed to work OK.
Am I missing something here?
Kris
--
Kris Heidenstrom Embedded systems designer / programmer
[email protected] Abbey Systems Ltd - Telemetry Specialists
Wellington NEW ZEALAND Voice +64-4-385-6611 Fax +64-4-385-6848
