【正文】 OV DPTR,TAB MOVC A,@A+DPTR MOV P0,A MOV P2,0FEH RET TAB:DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H,7FH,6FH TAB1:DB 0F7H,0C1H,0BBH,0EBH,0CDH,0EEH,0FEH,0C3H,0FFH,0EFH NOP END基于單片機的數(shù)字鐘設(shè)計 技術(shù)指標(biāo)設(shè)計要求的技術(shù)指標(biāo)有：①輸入脈沖幅度：05v②周期量測量范圍：—50ms③測量精度177。1%④顯示方式：四位數(shù)字顯示 ORG 0000H AJMP MAIN ORG 000BH AJMP PTF0 ORG 0033H TAB: DB 7EH,48H,3DH,6DH,4BH,67H,77H,4CH,7FH,6FH 。不帶小數(shù)點TAB1: DB 0BFH,86H,0DBH,0CFH,0E6H,0EDH,0FDH,87H,0FFH,0EFH 。帶小數(shù)點TAB2: DB 01H,02H,04H,08H,10H,20H,40H,80H,00H 。自檢ah PTF0: PUSH PSW 。保護現(xiàn)場PSW，ACC進棧 PUSH ACC 。選工作寄存器1區(qū) MOV TH0,0ECH 。T0初始化 MOV TL0,78H DJNZ 36H,PTFOR MOV 36H,92 。判斷中斷次數(shù)計數(shù)單元減1是否為0 XRL 33H,0FFH DJNZ 37H,PTFOR 。中斷次數(shù)計數(shù)單元36H，37H MOV 37H,2 MOV A,32H 。 秒單元32H加1 ADD A,1 DA A 。十進制調(diào)整 MOV 32H,A CJNE A,60H,PTFOR 。判斷單元是否計數(shù)到60 MOV 32H,0 MOV A,31H 。分單元31H加1 ADD A,1 DA A MOV 31H ,A CJNE A,60H,PTFOR MOV 31H ,0 MOV 32H ,0 MOV A,30H 。時單元30H加1 ADD A,1 DA A MOV 30H,A CJNE A,24H,PTFOR 。判斷計數(shù)單元是否到24 MOV 30H,0 MOV 31H,0 MOV 32H,0 PTFOR: POP ACC ?；謴?fù)現(xiàn)場，ACC，PSW退棧 POP PSW RETI MAIN: MOV P2,0FH 。數(shù)碼管自檢 MOV DPTR,TAB2 SS: MOV R2,00H SST: MOV A,R2 MOVC A,@A+DPTR JZ SS MOV P0,A INC R2 ACALL DEL3 MOV A,P0 CJNE A,80H,SST MOV 30H,00H 。狀態(tài)數(shù)初始化 MOV 31H,00H MOV 32H,00H MOV 33H,00H MOV 36H,92 MOV 37H,2 MOV SP,0EFH 。棧指針初始化 MOV TH0,0ECH MOV TL0,78H MOV TMOD,1 MOV IP,2 MOV IE,82H 。中斷初始化 SETB TR0 。允許T0計數(shù)LOOP: ACALL LOP0 JB ,XX 。校時按鍵按下但未松開（低電平）轉(zhuǎn)移到校時模塊 ACALL JS1XX: JB ,YY 。校分按鍵按下但未松開（低電平）轉(zhuǎn)移到校分模塊 ACALL JF1 ACALL LOP0YY: AJMP LOOP JS1: LCALL DEL JS2: JB , JS3 。校時按鍵松開（高電平）校時 ACALL LOP0 AJMP JS2 JS3: MOV A,30H ADD A,1 DA A MOV 30H,A CJNE A,24H,RT 。校時到24時，采用24進制計時 MOV 30H,0 JF1: LCALL DEL JF2: JB ,JF3 。校分按鍵松開（高電平）校分 ACALL LOP0 AJMP JF2JF3: MOV A,31H ADD A,1 DA A MOV 31H,A CJNE A,60H,RT 。分為60進制計時 MOV 31H,0 MOV A,30H INC A, MOV 30H,A 。分校時到60時 ，時自加一RT: RET LOP0: MOV R6,33H CJNE R6,00H,ZZ 。保證秒的閃爍，采用小數(shù)點的閃爍 MOV DPTR,TAB1 LJMP LOP1ZZ: MOV DPTR,TAB LOP1: MOV A,31H ANL A,0FH 。利用與 0F從中取出分個位，顯示分個位 MOVC A,@A+DPTR MOV P0,A MOV P2,0FFH MOV P2,0EFH 。保證數(shù)碼管的顯示不變，原理來源于任務(wù)5 ACALL DEL MOV A,31H ANL A,0F0H 。利用與F0相與 取出分十位，顯示分十位 SWAP A 。交換高低半字節(jié) MOVC A,@A+DPTR MOV P0,A MOV P2,0FFH MOV P2,0DFH ACALL DEL MOV A,30H 。時個位的顯示 （原理與分同） ANL A,00FH MOVC A,@A+DPTR MOV P0,A MOV P2,0FFH MOV P2,0BFH ACALL DEL