1、8255基本输入输出 能够在自行设计的接口开发板上,实现拨动开关控制LED的亮灭。 DATA SEGMENT DATA ENDS CODE SEGMENT ASSUME DS:DATA,CS:CODE START: MOV DX,0606H MOV AL,10000010B OUT DX,AL NEXT: MOV DX,0602H IN AL,DX MOV DX,0600H OUT DX,AL JMP NEXT MOV AH,4CH INT 21H CODE ENDS END START2、数码管应用     能够在自行设计的接口开发板上,数码管显示0到7,实现拨动不同开关,数码管显示该开关位置值(1-8)；若同时拨动两个以上开关,则数码管显示"E"

DATA SEGMENT NUM DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H,7FH,79H DATA ENDS CODE SEGMENT ASSUME DS:DATA,CS:CODE START: MOV AX,DATA MOV DS,AX MOV DX,0606H MOV AL,10010000B OUT DX,AL LOOP2: MOV DX,0600H IN AL,DX CMP AL,00000000B MOV SI,OFFSET NUM JZ NEXT MOV BL,AL SUB BL,1 AND BL,AL CMP BL,00000000B MOV SI,OFFSET NUM+9 JNZ NEXT MOV SI,OFFSET NUM+1 LOOP1: CMP AL,00000001B JZ NEXT SHR AL,1 INC SI JMP LOOP1 NEXT: MOV AL,[SI] MOV DX,0602H OUT DX,AL JMP LOOP2 MOV AH,4CH INT 21H CODE ENDS END START
3、汽车速度控制系统

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 DATA SEGMENT NUMS DB 3FH,06H,5BH,4FH,66h,6dh,7dh,07h,7fh,6fh,79H REAL DB 0,0,4,0,0,0 TARGET DB 0,0,0,0,0,0 WHICH DB 0 CLOCKER DB 0 DATA ENDS CODE SEGMENT ASSUME CS:CODE START: MOV DX, MY8255_MODE MOV AL, 81H OUT DX, AL MOV BX, 8001H MOV DX,MY8255_B MOV AL,0H OUT DX,AL CTRL: MOV SI,DATA MOV DS,SI MOV DX, MY8255_C IN AL, DX TEST AL,8H JNZ DANG_4 TEST AL,4H JNZ DANG_3 TEST AL,2H JNZ DANG_2 TEST AL,1H JNZ DANG_1 JMP DANG_0 DANG_0: MOV AL,0 MOV DI,OFFSET TARGET ADD DI,2H MOV DS:[DI],AL SAL AL,4 OUT DX,AL JMP STARTP DANG_1: MOV AL,1 MOV DI,OFFSET TARGET ADD DI,2H MOV DS:[DI],AL SAL AL,4 OUT DX,AL JMP STARTP DANG_2: MOV AL,2 MOV DI,OFFSET TARGET ADD DI,2H MOV DS:[DI],AL SAL AL,4 OUT DX,AL JMP STARTP DANG_3: MOV AL,4 MOV DI,OFFSET TARGET ADD DI,2H MOV DS:[DI],AL SAL AL,4 OUT DX,AL JMP STARTP DANG_4: MOV AL,8 MOV DI,OFFSET TARGET ADD DI,2H MOV DS:[DI],AL SAL AL,4 OUT DX,AL STARTP: MOV DI,OFFSET CLOCKER MOV AX,DS:[DI] CMP AX,0055H JZ CTINC INC AX MOV DS:[DI],AX CALL PRINTALL ;CALL DELAY JMP CTRL CTINC: MOV AX,0 MOV DS:[DI],AX CALL COMPARE CMP AX,1H JZ CTRDEC CMP AX,2H JZ CTRINC JMP CTRL CTRINC: CALL INCREMENT JMP CTRL CTRDEC: CALL DECREMENT J_END: JMP CTRL ;CALL DELAY: MOV CX, 00fFH AA2: LOOP AA2 RET INCREMENT:;AL is current bit MOV SI,DATA MOV DS,SI MOV AL,0 MOV AH,0 MOV DI,OFFSET REAL ADD DI,AX MOV AH,DS:[DI] INC AH MOV DS:[DI],AH ;increment lowest bit TOHIGH: ;AH is the value of current bit CMP AH,0AH JNZ INCEND MOV AH,0 MOV DS:[DI],AH ;set current bit 0 MOV BL,6 DEC BL CMP AL,BL ;whether is the highest bit JZ INCEND INC AL MOV BX,AX MOV DI,OFFSET REAL ADD DI,BX MOV AH,DS:[DI] INC AH MOV DS:[DI],AH ;;make higher bit inc JMP TOHIGH INCEND: RET DECREMENT: MOV SI,DATA MOV DS,SI MOV AL,0 MOV AH,0 MOV DI,OFFSET REAL ADD DI,AX MOV AH,DS:[DI] DEC AH MOV DS:[DI],AH ;increment lowest bit TODLOW: ;AH is the value of current bit CMP AH,00FFH JNZ DECEND MOV AH,9H MOV DS:[DI],AH ;set current bit 9 MOV BL,6 DEC BL CMP AL,BL ;whether is the highest bit JZ DECEND INC AL MOV AH,0 MOV BX,AX MOV DI,OFFSET REAL ADD DI,BX MOV AH,DS:[DI] DEC AH MOV DS:[DI],AH ;make higher bit inc JMP TODLOW DECEND: RET ;AX 1 bigger 2 smaller 0 equall COMPARE: MOV SI,DATA MOV DS,SI MOV BX,05H CMPSTART: CMP BX,00FFFFH JZ CMPEQUALLEND MOV DI,OFFSET REAL ADD DI,BX MOV AL,DS:[DI] MOV DI,OFFSET TARGET ADD DI,BX MOV AH,DS:[DI] CMP AL,AH JNLE CMPBIGEND JNGE CMPSMALLEND DEC BX JMP CMPSTART CMPBIGEND: MOV AX,1H RET CMPSMALLEND: MOV AX,2H RET CMPEQUALLEND: MOV AX,0H RET PRINTALL: MOV SI,DATA MOV DS,SI MOV BX,00H MOV AL,11011111B MOV DI,OFFSET WHICH MOV DS:[DI],AL PASTART: CMP BX,3H JZ PAEND MOV DX,MY8255_B MOV AL,11111111B OUT DX,AL MOV AH,0H MOV DI,OFFSET REAL ADD DI,BX MOV AL,DS:[DI] MOV SI,DATA MOV DI,OFFSET NUMS ADD DI,AX MOV DS,SI MOV AL,DS:[DI] MOV DX,MY8255_A OUT DX,AL MOV DX,MY8255_B MOV DI,OFFSET WHICH MOV AL,DS:[DI] OUT DX,AL ROR AL,1 MOV DS:[DI],AL INC BX JMP PASTART PAEND: RET CODE ENDS END START