1. 实验目的
- 本次试验利用8254,8255芯片，由8254产生1s方波接入中断，以此实现精确计时。8255芯片负责数码管显示及键盘扫描。
2. 已知BUG
- 设置计数初值时如果为XX00则会出现(XX-1)99的现象，应为(xx-1)59,只要后两位不是00则无此bug。
- 设置计数初值时没有对输入的数进行限制，可以输入9999这种初值，然而按理说最大应该是5959。
- 上述bug比较好改，然而老师都算我过了，我就不改了，希望各位改掉bug后留言，我将换上改好的代码。
3. 代码
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SSTACK ENDS PUBLIC SEC PUBLIC MIN PUBLIC STT PUBLIC TEMPP DATA SEGMENT DTABLE DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H,7FH,6FH MSEC DW 0 SEC DB 05H MIN DB 00H STT DB 01H TEMPP DB,00H DATA ENDS CODE SEGMENT ASSUME CS:CODE,DS:DATA,SS:SSTACK START: PUSH DS MOV AX, 0000H MOV DS, AX MOV AX, OFFSET MIR7 ;取中断入口地址 MOV SI, 003CH ;中断矢量地址 MOV [SI], AX ;填IRQ7的偏移矢量确定地址 MOV AX, CS ;段地址 MOV SI, 003EH MOV [SI], AX ;填IRQ7的段地址矢量 CLI POP DS ;初始化主片8255 MOV DX,MY8255_MODE MOV AL,81H OUT DX,AL ;初始化主片8254 MOV DX,CON8254 MOV AL,36H OUT DX,AL MOV DX,A8254 MOV AL,0E8H OUT DX,AL MOV AL,03H OUT DX,AL ;初始化主片8259 MOV AL, 11H OUT 20H, AL ;ICW1 MOV AL, 08H OUT 21H, AL ;ICW2 MOV AL, 04H OUT 21H, AL ;ICW3 MOV AL, 01H OUT 21H, AL ;ICW4 MOV AL, 6FH OUT 21H, AL ;OCW1 STI MOV AX,DATA MOV DS,AX MOV SI,3000H MOV AL,00H MOV [SI],AL MOV [SI+1],AL MOV [SI+2],AL MOV [SI+3],AL MOV DI,3003H BEGIN: CALL DIS CALL CLEAR CALL CCSCAN JNZ INK1 CMP STT,01H JNE BEGINCON STI BEGINCON: CMP STT,00H JNE BEGIN CLI JMP BEGIN INK1: CALL CCSCAN JNZ INK2 JMP BEGIN INK2: MOV CH,0FEH MOV CL,00H COLUM: MOV AL,CH MOV DX,MY8255_A OUT DX,AL MOV DX,MY8255_C IN AL,DX L1: TEST AL,01H ;is L1? JNZ L2 MOV AL,00H ;L1 JMP KCODE L2: TEST AL,02H ;is L2? JNZ L3 MOV AL,04H ;L2 JMP KCODE L3: TEST AL,04H ;is L3? JNZ L4 MOV AL,08H ;L3 JMP KCODE L4: TEST AL,08H ;is L4? JNZ NEXT MOV AL,0CH ;L4 KCODE: ADD AL,CL CALL PUTBUF PUSH AX KON: CALL DIS CALL CLEAR CALL CCSCAN JNZ KON POP AX NEXT: INC CL MOV AL,CH TEST AL,08H JZ KERR ROL AL,1 MOV CH,AL JMP COLUM KERR: JMP BEGIN PUTBUF: STTT: CMP STT,01H JNE CC CMP AL,0AH JB GOBACK CC: CMP AL,0CH JNE BB MOV AH,4CH INT 21H BB: CMP AL,0BH JNE AA CMP STT,00H JNE SET0 MOV STT,01H JMP GOBACK SET0: MOV STT,00H JMP GOBACK AA: CMP AL,0AH JNE PUTBUFCON TESTT: CMP STT,00H JE TESTTCON CALL FINISH JMP GOBACK TESTTCON: MOV STT,01H PUSH SI PUSH AX MOV SI,3000H MOV AL,[SI+1] ROL AL,4 MOV AH,[SI] ADD AL,AH MOV SEC,AL MOV AL,[SI+3] ROL AL,4 MOV AH,[SI+2] ADD AL,AH MOV MIN,AL POP AX POP SI JMP GOBACK PUTBUFCON: MOV SI,DI ;存键盘值到相应位的缓冲中 MOV [SI],AL DEC DI CMP DI,2FFFH JNZ GOBACK MOV DI,3003H GOBACK: RET MIR7: STI PUSH AX PUSH SI MOV AX,MSEC INC AX MOV MSEC,AX CMP AX,1000 JB MRET MOV AX,0 MOV MSEC,AX MOV AL,SEC SUB AL,1 DAS MOV SEC,AL CMP AL,01 JNB MTODIS MOV AL,MIN CMP AL,00 JNE CONTINUE CALL FINISH JMP MRET CONTINUE: SUB AL,1 DAS MOV MIN,AL MOV AL,00H MOV SEC,AL MOV AL,00H MOV SEC,AL ADD AL,59H DAA MOV SEC,AL MTODIS: MOV AL,SEC MOV AH,AL MOV SI,3000H AND AL,0FH MOV [SI],AL ROR AH,1 ROR AH,1 ROR AH,1 ROR AH,1 AND AH,0FH MOV [SI+1],AH MOV AL,MIN MOV AH,AL AND AL,0FH MOV [SI+2],AL ROR AH,1 ROR AH,1 ROR AH,1 ROR AH,1 AND AH,0FH MOV [SI+3],AH MRET: MOV AL, 20H OUT 20H, AL ;中断结束命令 POP SI POP AX IRET CLEAR: MOV DX,MY8255_B MOV AL,00H OUT DX,AL RET DIS: PUSH AX MOV SI,3000H MOV DL,0F7H MOV AL,DL AGAIN: PUSH DX MOV DX,MY8255_A OUT DX,AL MOV AL,[SI] MOV BX,OFFSET DTABLE AND AX,00FFH ADD BX,AX MOV AL,[BX] MOV DX,MY8255_B OUT DX,AL CALL DALLY INC SI POP DX MOV AL,DL TEST AL,01H JZ OUT1 ROR AL,1 MOV DL,AL JMP AGAIN OUT1: POP AX RET DALLY: PUSH CX MOV CX,000FH T1: MOV AX,002FH T2: DEC AX JNZ T2 LOOP T1 POP CX RET DELAY: PUSH CX MOV CX,00FFH T3: MOV AX,02FFH T4: DEC AX JNZ T4 LOOP T3 POP CX RET CCSCAN: MOV AL,00H ;键盘扫描子程序 MOV DX,MY8255_A OUT DX,AL MOV DX,MY8255_C IN AL,DX NOT AL AND AL,0FH RET FINISH: CLI PUSH AX MOV AL,00H PUSH SI MOV SI,3000H MOV [SI],AL MOV [SI+1],AL MOV [SI+2],AL MOV [SI+3],AL POP SI MOV SEC,AL MOV MIN,AL PUSH CX CALL CLEAR CALL DELAY MOV CX,003FH T5: CALL DIS LOOP T5 CALL CLEAR CALL DELAY MOV CX,003FH T6: CALL DIS LOOP T6 CALL CLEAR CALL DELAY MOV CX,003FH T7: CALL DIS LOOP T7 POP CX POP AX MOV STT,00H RET CODE ENDS END START |
有没有线的连接。。。快gg了
时间太久远了，都忘得差不多了