Hello, I'm working on the XC164X µc and I've a question concerning the storage of registers in stack when interrupt occur.
The function is written in c language
void ItFunc (void) interrupt 14 { funcCode (); }
The pre-processor code is as follow:
ItFunc PROC INTERRUPT = 14 GLOBAL ItFunc ; FUNCTION ItFunc (BEGIN RMASK = @0x3FFF)
SCXT DPP3,#3
PUSH DPP0
SCXT MDC,#16
PUSH MDH
PUSH MDL
MOV [-R0],R1
MOV [-R0],R2
MOV [-R0],R3
MOV [-R0],R4
MOV [-R0],R5
MOV [-R0],R6
MOV [-R0],R7
MOV [-R0],R8
MOV [-R0],R9
MOV [-R0],R10
MOV [-R0],R11
MOV [-R0],R12
; line 234: funcCode ();
CALL funcCode
?C0005:
MOV R12,[R0+]
MOV R11,[R0+]
MOV R10,[R0+]
MOV R9,[R0+]
MOV R8,[R0+]
MOV R7,[R0+]
MOV R6,[R0+]
MOV R5,[R0+]
MOV R4,[R0+]
MOV R3,[R0+]
MOV R2,[R0+]
MOV R1,[R0+]
POP MDL
POP MDH
POP MDC
POP DPP0
POP DPP3
RETI
; FUNCTION ItFunc (END RMASK = @0x3FFF)
ItFunc ENDP
?PR?BS_TST ENDS
As shown in this pre-processor code, we use the register R0 to save the registers R1—R12. I'd like to store the registers using the instruction PUSH R1. How can I do this? Which directive could I use that the compiler store the registers in stack using the instruction "PUSH R1" and not using "MOV [-R0], R1"
Thanks
the compiler don't decides what to do, we use directives and configuration to assisit compiler what to do.
so please, the question is clear, why turn arround??
I understand what your trying to do; give a hint to the compiler to use PUSH (system stack) instead of MOV (user stack). But it's a hint so the compiler can still decide to do otherwise.
Could you answer me/us this: -why- do you want the compiler to use PUSH instead of MOV? I don't see why it's important in the first place.
Is not important if we store registers using push or mov R0, just i'm curious to know why there are two possibility to stores registers in stack. so I think there's an option to check off to tell compiler when using push or mov R0.
thanks for advising me to use pre> to post code, it's the first time that I post in this forum.
There is checkbox in the Options for target/C166
"Save temporary variables on User Stack" If it is checked, then all registers are placed in User Stack, i.e commands like mov [-R0], Rx are used. If unchecked, then push/pop commands are used instead.
Thanks Andrey!
For those people who do not use the IDE :-) it's the SAVESYS and SAVEUSR compiler directive. I completly missed those...
See http://www.keil.com/support/man/docs/c166/c166_cm_directives.htm
Thanks MOMO, I learned something new because of your post.
-- Joost
yes, finally
thanks for you