按鍵開關消抖程序

源代碼：

led1bitP2.0
led2bitP2.1
switch1bitP1.0
ORG 0000h
setb switch1//initialize switch 1 as input
setb led1//Turn OFF LED1
setb led2//Turn OFF LED2

wait:
jb switch1,wait// Wait till switch1 has been pressed
call debounce_delay
jb switch1,c1_wait
//switch low even after debouncing period
//switch has been succesfully debounced
clr led1//Turn ON LED1
jnb switch1,$//wait till switch has been released
setb led1//Turn OFF LED1
ajmp wait

c1_wait:
//Switch PIN high after debounce period so error in debouncing
cpl led2
ajmp wait

debounce_delay://Subroutine for generating 20ms delay
mov r7,#245
l1_debounce_delay:
mov r6,#40
djnz r6,$
djnz r7,l1_debounce_delay
ret

END