mc8051fun/long_xsub.c
2024-06-05 08:19:50 +02:00

29 lines
248 B
C

/**
* @r0=@r0-@r1
* r7=len
*/
void long_xsub() __naked
{
__asm
.globl long_xsub
.globl long_xsubb
long_xsub:
clr c
long_xsubb:
movx a,@r1
mov b,a
movx a,@r0
subb a,b
movx @r0,a
inc r0
inc r1
djnz r7,long_xsubb
ret
__endasm;
}