
Known limitations ST72321xx-Auto
236/243 Doc ID 13829 Rev 1
; check the semaphore status if edge is detected
CP A,#01
jrne OUT
call call_routine
; call the interrupt routine
OUT:LD A,#00
LD sema,A
.call_routine
; entry to call_routine
PUSH A
PUSH X
PUSH CC
.ext1_rt
; entry to interrupt routine
LD A,#00
LD sema,A
IRET
Case 2: Writing to PxOR or PxDDR with global interrupts disabled:
SIM
; set the interrupt mask
LD A,PFDR
AND A,#$02
LD X,A
; store the level before writing to PxOR/PxDDR
LD A,#$90
LD PFDDR,A
; Write into PFDDR
LD A,#$ff
LD PFOR,A
; Write to PFOR
LD A,PFDR
AND A,#$02
LD Y,A
; store the level after writing to PxOR/PxDDR
LD A,X
Komentáře k této Příručce