deng.asm

根据8051单片机的特点及交通灯在实际控制中的特点

                ORG 0000H
                AJMP MAIN
                ORG 000BH
                AJMP FT0
                ORG 0030H
MAIN:           MOV SP,#60H
                MOV DPTR,#TAB
                MOV 30H,#29
                CLR P1.0
                SETB P1.1
                SETB P1.2
                SETB P1.3
                SETB P1.4
                CLR P1.5
                MOV TMOD,#02H
                MOV TH0,#164
                MOV TL0,#164
                SETB ET0
                SETB TR0
                SETB EA
                MOV 40H,#100
                MOV 41H,#100
                SETB 20H.0
                SETB 20H.1

LOOP:           ACALL DIVI
                ACALL DISP
                AJMP LOOP

DIVI:           MOV A,30H
                MOV B,#10
                DIV AB
                MOV R3,A
                MOV R2,B
                RET

DISP:           SETB P1.6
                MOV A,02H
                MOVC A,@A+DPTR
                MOV P0,A
                ACALL DELAY1MS
                SETB P1.7
                MOV A,03H
                MOVC A,@A+DPTR
                MOV P0,A
                ACALL DELAY1MS
                RET

FT0:            DJNZ 40H,EXIT
                MOV 40H,#100
                DJNZ 41H,EXIT
                MOV 41H,#100
                DEC 30H
                MOV R7,30H
                CJNE R7,#0,EXIT
                JNB 20H.0,M0
                JNB 20H.1,M1
                CPL P1.0
                CPL P1.1
                MOV 30H,#4
                CPL 20H.0
                AJMP EXIT

M0:             CPL 20H.0
                CPL 20H.1
                CPL P1.1
                CPL P1.5
                CLR P1.2
                CPL P1.3
                SETB
                MOV 30H,#24
                AJMP EXIT

M1:             CPL 20H.1
                
                CPL P1.3
                CPL P1.4

                MOV 30H,#29

EXIT:           RETI


DELAY1MS:       MOV 42H,#18
L1:             MOV 43H,#25
L0:             DJNZ 43H,L0
                DJNZ 42H,L1
                RET

TAB:            DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H,7FH,6FH

                END