51單片機LED管顯示子程序實例

;DISP顯示子程序

PORT_AEQU0CF01H

PORT_BEQU0CF02H

PORT_CEQU0CF03H

;功能:將顯示緩沖區(qū)39-3FH內容顯示一遍

;3FH對應八個LED管

;3E-39H自左到右對應數(shù)碼

;占用:PSW,ACC,DPTR,R0,R3,R6,R7內

;

ORG0DE00H

DISP1:MOVR0,#3FH

DISP_0:MOVR3,#01000000B;位選字

MOVA,@R0;取顯示數(shù)據(jù)

SJMPDISP_2

DISP_1:MOVDPTR,#LED_TB

MOVA,@R0

MOVCA,@A+DPTR

DISP_2:CPLA;字型求反

MOVDPTR,#PORT_B

MOVX@DPTR,A;字型送8155B口

MOVA,R3

DECDPL

MOVX@DPTR,A;位選字送8155A口

LCALLD1MS;延時1MS

CLRA

MOVDPTR,#PORT_A

MOVX@DPTR,A;關顯示

DECR0

MOVR3,A

RRA

MOVA,R3

JNBACC.7,DISP_1

MOVA,R0

ADDA,#7

MOVR0,A

RET

D1MS:MOVR6,#0

DJNZR6,$

RET

;

;顯示字型表

ORG0130H

LED_TB:DB3FH,06H,5BH,4FH;0123

DB66H,6DH,7DH,07H;4567

DB7FH,6FH,77H,7CH;89AB

DB39H,5EH,79H,71H;CDEF

DB00H,73H,58H,4CH;_P [ ]

DB76H,5EH;HD