ST7MC2S4 STMicroelectronics, ST7MC2S4 Datasheet - Page 305

• Manufacturer Part Number: ST7MC2S4
• Description: 8-BIT MCU WITH NESTED INTERRUPTS, FLASH, 10-BIT ADC,BRUSHLESS MOTOR CONTROL, 5 TIMERS, SPI, LINSCI(TM)
• Manufacturer: STMicroelectronics

LD PFDDR,A; Write into PFDDR
LD A,#$ff
LD PFOR,A
LD A,PFDR
AND A,#$02
LD Y,A
PxDDR
LD A,X
cp A,#$02
jrne OUT
TNZ Y
jrne OUT
LD A,#$01
LD sema,A ; set the semaphore to '1' if edge is
detected
RIM
LD A,sema ; check the semaphore status
; store the level after writing to PxOR/
; check for falling edge
; reset the interrupt mask
; Write to PFOR
CP A,#$01
jrne OUT
call call_routine; call the interrupt routine
RIM
OUT:
JP while_loop
.call_routine ; entry to call_routine
PUSH A
PUSH X
PUSH CC
.ext1_rt
LD A,#$00
LD sema,A
IRET
RIM
; entry to interrupt routine
ST7MC1xx/ST7MC2xx
305/309