數(shù)碼顯示管顯示按鍵總個數(shù) 89c51單片機編程實例

;AT89C51單片機P1口接8個按鍵（switch），P2口接1個共陰極數(shù)碼顯示管，數(shù)碼顯示管顯示按鍵按下的個數(shù)

;注：連接電路圖時，將實例2.1中的八個button按鍵換成switch按鍵

org 00h
sjmp start
org 30h
start: mov p2,#3fh
mov dptr,#table
cc: mov r3,#0
next: mov a,p1
cpl a
clr c
mov r4,#8
bb: rlc a
jnc aa
inc r3
aa: djnz r4, bb
mov a,r3
movc a,@a+dptr
mov p2,a
sjmp cc
delay: mov r6,#50
d1: mov r7,#100
djnz r7,$
djnz r6,d1
djnz r5,delay
ret
table:db 3fh,06h,5bh,4fh,66h,6dh,7dh,07h,7fh
end