;4-bit lcd code for 16x2 and 16x4 display (hd44780 compatable lcd) ;pin configuration ;P1.7 --------> DB7 ;P1.6 --------> DB6 ;P1.5 --------> DB5 ;P1.4 --------> DB4 ;P3.7 --------> EN ;P3.5 --------> RS ;P3.4 --------> RW org 0000h ljmp main org 0030h main: nop en equ p3.7 rs equ p3.5 rw equ p3.4 dat equ p1 lcall lcd_int again: lcall clear lcall line1 mov dptr,#mydata lcall loop lcall line2 mov dptr,#mydat2 lcall loop ;lcall line3 ;(16x4) ;mov dptr,#mydat3 ;(16x4) ;lcall loop ;(16x4) ;lcall line4 ;(16x4) ;mov dptr,#mydat4 ;(16x4) ;lcall loop ;(16x4) lcall line1 mov dptr,#mydat5 lcall loop lcall line2 mov dptr,#mydat6 lcall loop ;lcall line3 ;(16x4) ;mov dptr,#mydat7 ;(16x4) ;lcall loop ;(16x4) ;lcall line4 ;(16x4) ;mov dptr,#mydat8 ;(16x4) ;lcall loop ;(16x4) sjmp again w_nib: push acc ;save a for low nibble orl dat,#0f0h ;bits 4..7 <- 1="" td=""> orl a,#0fh ;don't affect bits 0-3 anl dat,a ;high nibble to display setb en clr en pop acc ;prepare to send swap a ;...second nibble orl dat,#0f0h ; bits 4...7 <- 1="" td=""> orl a,#0fh ; don't affect bits 0...3 anl dat,a ;low nibble to display setb en clr en ret lcd_int: clr rs clr rw clr en setb en mov dat,#028h clr en lcall sdelay mov a,#28h lcall com mov a,#0ch lcall com mov a,#06h lcall com lcall clear mov a,#080h lcall com ret clear: clr rs mov a,#01h lcall com ret dataw: setb rs clr rw lcall w_nib lcall ldelay ret sdelay: mov r6,#1 here2: mov r7,#255 here: djnz r7,here djnz r6,here2 ret ldelay: mov r6,#100 her2: mov r7,#255 her: djnz r7,her djnz r6,her2 ret com: clr rs clr rw lcall w_nib lcall sdelay ret line1: mov a,#002h lcall com ret line2: mov a,#0c0h lcall com ret line3: mov a,#090h lcall com ret line4: mov a,#0d0h lcall com ret loop: clr a movc a,@a+dptr jz go_b2 lcall dataw lcall sdelay inc dptr sjmp loop go_b2: ret mydata: db " line1 ",0 mydat2: db " line2 ",0 mydat3: db " line3 ",0 mydat4: db " line4 ",0 mydat5: db " line5 ",0 mydat6: db " line6 ",0 mydat7: db " line7 ",0 mydat8: db " line8 ",0
Related topics:
8051 Program - 8 bit lcd code | 8051 Program - running led | 8051 Program - 32bit multiplication | 8051 Program - memory subroutines | 8051 Program - math subroutines | 8051 Program - conversion subroutines
List of topics: 8051
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