1.sdi

这是一个实现串口通讯的实验

,,,LINE    EQU     30H
,,,ROW     EQU     31H
,,,ORG     00H
0000,,START,START:
0000,75 A0 00,,        MOV     P2,#00H         ;数码管显示初始化
0003,75 80 00,,        MOV     P0,#00H
0006,D2 B7,,        SETB     P3.7
0008,75 90 F0,LSCAN,LSCAN:  MOV     P1,#0F0H        ;列线置高电平,行线置低电平
000B,30 90 0C,L1,L1:     JNB     P1.0,L2         ;逐行扫描
000E,12 00 A3,,        LCALL   DELAY
0011,30 90 06,,        JNB     P1.0,L2
0014,75 30 00,,        MOV     LINE,#00H       ;存行号
0017,02 00 44,,        LJMP    RSCAN
001A,30 91 0C,L2,L2:     JNB     P1.1,L3
001D,12 00 A3,,        LCALL   DELAY
0020,30 91 06,,        JNB     P1.1,L3
0023,75 30 01,,        MOV     LINE,#01H       ;存行号
0026,02 00 44,,        LJMP    RSCAN
0029,30 92 0C,L3,L3:     JNB     P1.2,L4
002C,12 00 A3,,        LCALL   DELAY
002F,30 92 06,,        JNB     P1.2,L4
0032,75 30 02,,        MOV     LINE,#02H       ;存行号
0035,02 00 44,,        LJMP    RSCAN
0038,30 93 D0,L4,L4:     JNB     P1.3,L1
003B,12 00 A3,,        LCALL   DELAY
003E,30 93 CA,,        JNB     P1.3,L1
0041,75 30 03,,        MOV     LINE,#03H       ;存行号
0044,75 90 0F,RSCAN,RSCAN:  MOV     P1,#0FH         ;行线列线电平互换
0047,30 94 06,C1,C1:     JNB     P1.4,C2         ;逐列扫描
004A,75 31 00,,        MOV     ROW,#00H        ;存列号
004D,02 00 68,,        LJMP    CALCU
0050,30 95 06,C2,C2:     JNB     P1.5,C3
0053,75 31 01,,        MOV     ROW,#01H        ;存列号
0056,02 00 68,,        LJMP    CALCU
0059,30 96 06,C3,C3:     JNB     P1.6,C4
005C,75 31 02,,        MOV     ROW,#02H        ;存列号
005F,02 00 68,,LJMP    CALCU
0062,30 97 E2,C4,C4:     JNB     P1.7,C1
0065,75 31 03,,        MOV     ROW,#03H        ;存列号
0068,E5 30,CALCU,CALCU:  MOV     A,LINE          ;根据行号和列号计算按键编码
006A,75 F0 04,,        MOV     B,#04H
006D,A4,,        MUL     AB
006E,25 31,,        ADD     A,ROW
0070,75 89 20,,        MOV     TMOD,#20H
0073,75 8D E6,,        MOV     TH1,#0E6H
0076,75 8B E6,,        MOV     TL1,#0E6H
0079,D2 8E,,        SETB    TR1
007B,75 98 50,,        MOV     SCON,#50H
007E,F5 99,,        MOV     SBUF,A
0080,10 99 02,G0,G0:     JBC     TI,G1
0083,01 80,,        AJMP    G0
0085,10 98 02,G1,G1:     JBC     RI,G2
0088,01 85,,        AJMP    G1
008A,E5 99,G2,G2:     MOV     A,SBUF
008C,B2 B7,,        CPL     P3.7
008E,20 B7 09,,        JB      P3.7,S0
0091,F5 A0,,        MOV     P2,A
0093,11 A3,,        ACALL   DELAY
0095,11 A3,,        ACALL   DELAY
0097,02 00 08,,        LJMP    LSCAN
009A,F5 80,S0,S0:     MOV     P0,A
009C,11 A3,,        ACALL   DELAY
009E,11 A3,,        ACALL   DELAY
00A0,02 00 08,,        LJMP    LSCAN
00A3,7E 50,DELAY,DELAY:  MOV     R6,#80
00A5,7F FA,D1,D1:     MOV     R7,#250
00A7,DF FE,,        DJNZ    R7,$
00A9,DE FA,,        DJNZ    R6,D1
00AB,22,,        RET
000E,,,END
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