;4X4 行列矩阵键盘*行扫描法* .MODEL SMALL .DATA ASCTABLE DB '0123456789ABCDER' CTRL EQU 0C803H PA EQU 0C800H PB EQU 0C801H PC EQU 0C802H .CODE .STARTUP START: MOV DX,CTRL ;设置 8255 的 PC 为列线输入，PB 为行线输出 MOV AL,89H OUT DX,AL NEXT: MOV DX,PB MOV AL,0 OUT DX,AL MOV DX,PC AB: IN AL,DX AND AL,0FH CMP AL,0FH JZ AB MOV CX,0;闭合延时去抖 LOOP DELAY1 DELAY1: MOV BH,0 MOV BL,0 MOV CX,4 MOV AH,0FEH AGAIN: MOV AL,AH MOV DX,PB OUT DX,AL MOV DX,PC IN AL,DX AND AL,0FH CMP AL,0FH JNZ AB1 ADD BH,4 ROL AH,1 LOOP AGAIN JMP NEXT 

AB1: AB3: MOV CX,4 SHR AL,1 JC AB2 JMP AB4 AB2: INC BL LOOP AB3 AB4: ADD BH,BL MOV AL,BH LEA BX,ASCTABLE XLAT MOV DL,AL MOV AH,2 INT 21H push dx MOV CX,0 ;释放延时去抖 DELAY2: LOOP DELAY2 AB5: MOV DX,PC IN AL,DX AND AL,0FH CMP AL,0FH JNZ AB5 pop dx CMP dl,'R' JNZ NEXT .EXIT 0 ex: END