微机原理与接口技术交通灯控制

DJNZ R4,WAIT4 CPL P2.6 MOV R4,#4 DJNZ R2,WAIT4 MOV R2,#5 DEC 30H DEC 31H LCALL DISPLAY DJNZ R3,WAIT4 LJMP LOOP S1 : MOV P2,#0EBH RET S2 : MOV P2,#0E7H RET S3 : MOV P2,#0DDH RET S4 : MOV P2,#0BDH RET DISPLAY : MOV A,30H MOV B,#10 DIV AB MOV 43H,A MOV A,B MOV 42H,A MOV A,31H MOV B,#10 DIV AB MOV 41H,A