數(shù)碼顯示管顯示按鍵序號(hào) 89c51單片機(jī)編程實(shí)例

題目：AT89C51單片機(jī)P1口接8個(gè)按鍵（button），P2口接1個(gè)共陰極數(shù)碼顯示管，當(dāng)有鍵按下時(shí)，數(shù)碼顯示管顯示按鍵的序號(hào)

電路圖：

源碼如下：

org 00h
sjmp start
org 30h
start:

mov P2,#00h
start1:
mov r1,#00h
mov dptr,#table
next:

mov a,p1
cpl a
jz next
mov r5,#1
acall delay
mov a,p1
cpl a
jz next
clr c
shift:

rrc a
jc display
inc r1
sjmp shift
display:
mov a,r1
movc a,@a+dptr
mov p2,a
again:

mov a,p1
cpl a
jnz again
sjmp start1
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
end