I have designed 2 short asm modules for copy data from code or xdata.?

My goal is to replace the generic memcpy () and memset() library functions for most cases.

While this is working well I have some doubts if this is interrupt save. I dont plan to use that special

auto inc feature?bDPTR_AUTO_INC because i think its not worth the trouble i might get.

;void?fastccpy8?(unsigned?char?xdata?*dest,?//r6r7????
;????????????????unsigned?char?code??*src,??//r4r5?????
;????????????????unsigned?char??size)???????//r3????????
sfr?XBUS_AUX?=?0xA2;?????
?PR?_fastccpy8?FASTCCOPY??SEGMENT?CODE????
PUBLIC	_fastccpy8????
$REGUSE?_fastccpy8(R7,A,DPTR)????

RSEG????PR?_fastccpy8?FASTCCOPY????
_fastccpy8:?????
???????MOV??XBUS_AUX,#0x01;?select?DPTR1,?no?auto?inc?????????
???????MOV??DPH,R6?????
???????MOV??DPL,R7?????;destination????
???????DEC??XBUS_AUX???;select?DPTR0????
???????MOV??DPH,?R4????
???????MOV??DPL,?R5????;source????
???????mov??A,R3????
???????MOV??R7,A???????
???????JZ????C001??????;nothing?todo?????
?C000:?CLR??A????
???????MOVC?A,@A+DPTR???;read?source????
???????INC??DPTR???????;no?autoinc?its?not?irq?save????
???????DB???0A5H???????;MOVX?@DPTR1,A?&?INC?DPTR1????
???????DJNZ?R7,?C000????
?C001:?RET

I have successfully testet that in interrupt functions as well as in main context, but i still have doubts if it is working correctly in

complex applications with irqs possibly set on different priorities.

There is a simlar function fastxcpy8 for copy from xdata

Any ideas are welcome.

donot doubts about auto inc,? these?instructions are single cycle.

but,?DPTR and DPTR1 are two reg,

ASM: in interrupt, you need save DPH/DPL if use DPTR in interrupt, just like using&saving B.

? ? ? and, if use the copy with DPTR1, u need save DPTR1 too, by save XBUS_AUX then select,

? ? ? save all regs u changed in interrupt.

keil C: it will save DPTR auto (if used), but not include DPTR1

so, 1. disable interrupt on copy entry, so not save DPTR1 & XBUS_AUX

2. or dont call the copy in interrupt

many thanks for your sugestions.?

I have compiled them into my code snippet. Cant find any downside exept after the first? calling of the copy function interrupts are globally enabled. This could be solved by reserving a bit in bit space for the EA state. I need to read the Keil docs about the correct syntax for that.

;void?fastccpy8?(unsigned?char?xdata?*dest,?//r6r7????
;????????????????unsigned?char?code??*src,??//r4r5?????
;????????????????unsigned?char??size)???????//r3????????
sfr?XBUS_AUX?=?0xA2;?????
?PR?_fastccpy8?FASTCCOPY??SEGMENT?CODE????
PUBLIC??_fastccpy8????
$REGUSE?_fastccpy8(R7,A,DPTR)????
?
RSEG????PR?_fastccpy8?FASTCCOPY????
_fastccpy8:?
???????CLR??EA??????
???????MOV??XBUS_AUX,#0x01;?select?DPTR1,?no?auto?inc
???????PUSH?DPH????????;save?old?DPTR1
???????PUSH?DPL?????????
???????MOV??DPH,R6?????
???????MOV??DPL,R7?????;destination????
???????DEC??XBUS_AUX???;select?DPTR0
???????SETB?EA????
???????MOV??DPH,?R4????
???????MOV??DPL,?R5????;source????
???????mov??A,R3????
???????MOV??R7,A???????
???????JZ????C001??????;nothing?todo?????
?C000:?CLR??A????
???????MOVC?A,@A+DPTR??;read?source????
???????INC??DPTR???????;no?autoinc?its?not?irq?save????
???????DB???0A5H???????;MOVX?@DPTR1,A?&?INC?DPTR1????
???????DJNZ?R7,?C000????
?C001:?CLR??EA?????????;restore?the?old?values
???????MOV??XBUS_AUX,#0x01
???????POP??DPL
???????POP??DPH
???????DEC??XBUS_AUX
???????SETB?EA
???????RET

so now 2 extra bytes in stack space are used (3 if i also save XBUS_AUX).

On the longterm I am planing to create device libs for the WCH chips with a bunch of functions. Similar to the WCH debug.c but sperately compiled as library.

FOR RE-ENTER SUBROUTINE (CALLED BY BOTH MAIN PROGRAM & INTERRUPT)

_fastccpy8:?

????? ? INC? DPTR

? ? ? ?DB???0A5H???????;MOVX?@DPTR1,A?&?INC?DPTR1? ??

? ? ? ?RET

OR:

_fastccpy8:?

???????MOVC?A,@A+DPTR??;read?source??

? ? ? ? ?INC DPTR??

? ? ? ?RET

does auto inc work on MOVC A,@A+DPTR too?

In the datasheet and h files auto inc is just mentioned for MOVX (CH552)

SORRY,? AUTO INC NOT SUPPORT MOVC