【正文】 DJNZ R4,NEXT9 MOV A,41H ADD A,01 DA A MOV 41H,A LJMP NEXT8 NEXT5:INC 42H MOV A,42H CJNE A,08H,NEXT11 MOV 42H,01H NEXT11:RET 。鍵盤掃描程序。****************************************************** KEY_SCAN:MOV P2,0F0H 。~ MOV A,P2 。讀P2口狀態(tài) ANL A,0F0H XRL A,0F0H JZ NO_KEY 。沒有鍵按下 LCALL DL10MS 。穩(wěn)定 MOV A,P2 ANL A,0F0H 。重讀鍵值 XRL A,0F0H JZ NO_KEY LCALL FENGMING 。沒有鍵按下 MOV R2,11110111B 。行掃描，從第三行開始 SCAN: MOV A,R2 MOV P2,A 。再次給P2口賦值 MOV A,P2 。讀P2口狀態(tài) ANL A,11110000B MOV R3,A CJNE A,0F0H,KEY_PRSD 。有鍵按下 MOV A,R2 RR A 。產(chǎn)生下次的行線輸出 MOV R2,A XRL A,01111111B 。檢測完否 JNZ SCAN NO_KEY:MOV R5,09H 。存放鍵值 RET KEY_PRSD:MOV A,R2 。取行掃描值 ANL A,00001111B 。計算行特征值 ORL A,R3 。計算行特征碼 MOV R4,A 。暫存 MOV R5,01H 。置按鍵鍵值初值 MOV DPTR,KEY_TAB 。特征碼表首地址 JIANCE:MOV A,R5 MOVC A,@A+DPTR XRL A,R4 JZ FIXED 。鍵值已經(jīng)找到 INC R5 MOV A,R5 CJNE A,07H,JIANCE 。七個鍵是否全部檢測完 AJMP NO_KEY FIXED:MOV P2,0F0H MOV A,P2 。判斷鍵是否釋放 ANL A,0F0H XRL A,0F0H JNZ FIXED LCALL DL10MS 。延時消抖 MOV A,P2 ANL A,0F0H XRL A,0F0H JNZ FIXED RET 。 節(jié)日提醒 JIERI:MOV R6,MON MOV R7,DAY LCALL YUANDAN LCALL YUREN LCALL LAODONG LCALL ERTONG RET YUANDAN:CJNE R6,01H,NEXT12 CJNE R7,01H,NEXT12 LCALL FENGMING LCALL FENGMING LCALL FENGMING RET YUREN : CJNE R6,04H,NEXT12 CJNE R7,01H,NEXT12 LCALL FENGMING LCALL FENGMING LCALL FENGMING RET LAODONG: CJNE R6,05H,NEXT12 CJNE R7,01H,NEXT12 LCALL FENGMING LCALL FENGMING LCALL FENGMING RET ERTONG:CJNE R6,06H,NEXT12 CJNE R7,01H,NEXT12 LCALL FENGMING LCALL FENGMING LCALL FENGMING RET NEXT12: RET 。報警程序。****************************************************FENGMING: MOV P1,00000111B ACALL DELY MOV P1,00000110B ACALL DELY DELY: MOV R3,100 DEL6: MOV R4,100 DEL7: NOP NOP NOP DJNZ R4,DEL7 DJNZ R3,DEL6 RET 。 顯示程序。**************************************************** DIS: MOV R0,22H MOV R2,06H 。地址和輸出初始化 NEXT1: MOV A,@R0 ANL A,0FH 。取低四位 ACALL DISP12 DEC R2 CJNE R2,00H,LOOP2 LJMP STOP LOOP2:MOV A,@R0 ANL A,0F0H SWAP A ACALL DISP11 DEC R2 DEC R0 CJNE R2,00H,NEXT1 LJMP STOP DISP11:MOV DPTR,SEG_TAB MOVC A,@A+DPTR MOV 26H,A LJMP NEXT2 。查得高四位的字型編碼 DISP12:MOV DPTR,SEG_TAB1 MOVC A,@A+DPTR MOV 26H,A LJMP NEXT2 。查的低四位的字型編碼 NEXT2: MOV A,R2 DEC A MOV P1,A NOP MOV A,26H MOV P0,A LJMP DL10MS RET DL1MS:MOV R0,20 DEL1:MOV R7,10 DEL0:NOP NOP NOP DJNZ R7,DEL0 DJNZ R0,DEL1 RET DL10MS:MOV R7,0C9H DLMS:NOP NOP NOP DJNZ R7,DLMS STOP:RET DL500MS: MOV R0,250 DELY1:MOV R7,250 DELY2:NOP NOP NOP NOP NOP NOP DJNZ R7,DELY2 DJNZ R0,DELY1 RETSEG_TAB:DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H,7FH,6FH 。高位編碼表SEG_TAB1:DB 0BFH,86H,0DBH,0CFH,0E6H,0EDH,0FDH,87H,0FFH,0EFH 。 低位編碼表 RETKEY_TAB: DB 00H,77H,07BH,7DH,0B7H,0BBH,0BDH,0D7H 。按鍵鍵值表，1~7七個鍵值TABLE:DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H,7FH,6FH,00H,39H,40H TABLE1:DB 00H,01H,02H,03H,04H,05H,06H,07H,08H,09H,10H,11H,12H DB 13H,14H,15H,16H,17H,18H,19H,20H,21H,22H,23H,24H,25H DB 26H,27H,28H,29H,30H,31H,32H,33H,34H,35H,36H,37H,38H DB 39H,40H,41H,42H,43H,44H,45H,46H,47H,48H,49H,50H ；外部中斷部分 ExtInt: PUSH ACC PUSH PSW SETB RS0 CLR RS1 SETB MOV R5,50H LD: MOV P0,00H LCALL FENGMING LCALL DL500MS DJNZ R5,LD POP PSW POP ACC RETI END參考文獻(xiàn)[1]段晨東.《單片機(jī)原理及接口技術(shù)》.北京:清華大學(xué)出版社,2008[2]周潤景 郝曉霞.《傳感器及檢測技術(shù)》.北京:電子工業(yè)出版社,2009[3]樓然苗 李光飛.《51系列單片機(jī)設(shè)計實例》.北京: 北京航天航空大學(xué)出版社,200640 / 40