单片机课程设计---简易数字秒表的设计与仿真

LED显示子程序： ORG 0300H DISP:MOV R0,#79H MOV R3,#0FEH LD0:MOV A,R3 MOV DPTR,#0FF20H MOVX @DPTR,A MOV DPTR,#SEG MOV A,@R0 DIR0:MOVC A,@A+DPTR MOV DPTR,#0FF21H DIR1:MOVX @DPTR,A ACALL DL INC R0 MOV A,R3 JNB ACC.5,LD1 RL A MOV R3,A LJMP LD0 LD1:RET 延时子程序： DL:MOV R6,#01FH DELAY2:MOV R7,#018H DELAY1:DJNZ R7,DELAY1 DJNZ R6,DELAY2 RET 字符’0’~’9‘的七段LED代码表： SEG:DB 0C0H,0F9H,0A4H,0B0H DB 99H,92H,82H,0F8H,80H,90H DB 0C0H,0F9H,0A4H,0B0H DB 99H,92H,82H,0F8H,80H,90H END