1. 实验目的
- 了解键盘扫描及数码显示的基本原理，熟悉 8255 的编程。
2. 实验内容
- 题目1：：将键盘进行编号，记作 0～F，当按下其中一个按键时，将该按键对应的编号在一个数码管上显示出来，当再按下一个按键时，便将这个按键的编号在下一个数码管上显示出来。
- 注：因为想做实验十，老师说实验十做出来平时成绩给满分，所以本次试验只做了一个了解一下基本原理就不做了。
3. 实验1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 | MY8255_A EQU 0600H MY8255_B EQU 0602H MY8255_C EQU 0604H MY8255_CON EQU 0606H SSTACK SEGMENT STACK DW 16 DUP(?) SSTACK ENDS DATA SEGMENT DTABLE DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H, 7FH,6FH,77H,7CH,39H,5EH,79H,71H DATA ENDS CODE SEGMENT ASSUME CS:CODE,DS:DATA START: MOV AX,DATA MOV DS,AXMOV -SI,3000H MOV AL,00H MOV [SI],AL ;清显示缓冲 MOV [SI+1],AL MOV [SI+2],AL MOV [SI+3],AL MOV [SI+4],AL MOV [SI+5],AL MOV DI,3005H MOV DX,MY8255_CON ;写 8255 控制字 MOV AL,81H OUT DX,AL BEGIN: CALL DIS ;调用显示子程序 CALL CLEAR ;清屏 CALL CCSCAN ;扫描 JNZ INK1 JMP BEGIN INK1: CALL DIS CALL DALLY CALL DALLY CALL CLEAR CALL CCSCAN JNZ INK2 ;有键按下，转到 INK2 JMP BEGIN ;确定按下键的位臵 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 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 CLEAR: MOV DX,MY8255_B ;清屏子程序 MOV AL,00H OUT DX,AL RET DIS: PUSH AX ;显示子程序 MOV SI,3000H MOV DL,0DFH 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 ;延时子程序 MOV CX,0006H T1: MOV AX,009FH T2: DEC AX JNZ T2 LOOP T1 POP CX RET PUTBUF: 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,3005H GOBACK: RET CODE ENDS END START |
