lcdsecond.asm

HD44780在aduc812上的应用

$MOD812

COM   EQU   20H
DAT   EQU   21H
RS    EQU   P2.5
RW    EQU   P2.6
E     EQU   P2.7

       MOV  SP,#60H
       MOV  P0,#30H
       CLR  RS
       CLR  RW
       MOV  R2,#03H
INT11: SETB E
       CLR  E
       LCALL DELAY
       DJNZ R2,INT11
       MOV  P0,#38H
       SETB E
       CLR  E
       MOV COM,#01H
       LCALL PR1
       MOV COM,#04H
       LCALL PR1
       MOV COM,#0FH
       LCALL PR1


CL_ENTER: MOV   COM,#04H
          LCALL PR1
          MOV   COM,#90H
          LCALL PR1
          MOV   DPTR,#TABCL
          MOV   R2,#12H
CL_1:     MOV   A,R2
          DEC   A
          MOVC  A,@A+DPTR
          MOV   DAT,A
          LCALL PR2
          LCALL DELAY
          DJNZ  R2,CL_1
          SJMP  $
TABCL:DB 43H,75H,72H,73H,6FH,72H,20H;CURSOR
      DB 4CH,65H,66H,74H,20H;LEFT
      DB 53H,63H,72H,6FH,6CH,6CH;SCROLL


  PR1:PUSH ACC
      CLR  RS
      SETB RW
 PR11:MOV  P0,#0FFH
      SETB E
      MOV  A,P0
      CLR  E
      JB   ACC.7,PR11
      CLR  RW
      MOV  P0,COM
      SETB E
      CLR  E
      POP  ACC
      RET

  PR2:PUSH ACC
      CLR  RS
      SETB RW
 PR21:MOV  P0,#0FFH
      SETB E
      MOV  A,P0
      CLR  E
      JB   ACC.7,PR21
      SETB RS
      CLR  RW
      MOV  P0,DAT
      SETB E
      CLR  E
      POP  ACC
      RET

DELAY: MOV  R6,#00H
       MOV  R7,#00H
DELAY1:NOP
       DJNZ R7,DELAY1
       DJNZ R6,DELAY1
       RET