简易版8人抢答器教程：包含汇编语言实现及电路图纸详细讲解

IOY0 EQU 0600H ;片选IOY0对应的端口始地址
MY8255_A EQU IOY0+00H*2 ;8255的A口地址
MY8255_B EQU IOY0+01H*2 ;8255的B口地址
MY8255_C EQU IOY0+02H*2 ;8255的C口地址
MY8255_MODE EQU IOY0+03H*2 ;8255的控制寄存器地址

SSTACK SEGMENT STACK
DW 32 DUP(?)
SSTACK ENDS
CODE SEGMENT
ASSUME CS:CODE
START:
MOV DX, MY8255_MODE
MOV AL, 90H
OUT DX, AL
AA1:
MOV DX,MY8255_A
IN AL,DX

CALL DELAY

CMP AL,00H ;判断开关是否按下
JZ AA1
CMP AL,01H ;按下的是第一个开关 0000 0001
JZ T1
CMP AL,02H ;按下的是第二个开关 0000 0010
JZ T2
CMP AL,04H ;按下的是第三个开关 0000 0100
JZ T3
CMP AL,08H ;按下的是第四个开关 0000 1000
JZ T4
CMP AL,10H ;按下的是第五个开关 0001 0000
JZ T5
CMP AL,20H
JZ T6
CMP AL,40H
JZ T7
CMP AL,80H
JZ T8

T1: ;若按下的是第一个 则显示1 送06H给B口
MOV AL,06H
MOV DX,MY8255_B
OUT DX,AL
JMP AA1
T2:
MOV AL,5BH
MOV DX,MY8255_B
OUT DX,AL
JMP AA1

T3:
MOV AL,4FH
MOV DX,MY8255_B
OUT DX,AL
JMP AA1
T4:
MOV AL,66H
MOV DX,MY8255_B
OUT DX,AL
JMP AA1
T5:
MOV AL,6DH
MOV DX,MY8255_B
OUT DX,AL
JMP AA1
T6:
MOV AL,7CH
MOV DX,MY8255_B
OUT DX,AL
JMP AA1
T7:
MOV AL,07H
MOV DX,MY8255_B
OUT DX,AL
JMP AA1
T8:
MOV AL,7FH
MOV DX,MY8255_B
OUT DX,AL
JMP AA1
DELAY: PUSH CX
MOV CX, 0F000H
AA2: PUSH AX
POP AX
LOOP AA2
POP CX
RET
CODE ENDS
END START