PIC microcontroller LCD1602 display

P IC  single chip  LCD 1602 displays the website address and phone number

;************************************
PCL EQU 2H ;Define the low byte address of program memory
STATUS EQU 3H ;Define the status register address
PORTD EQU 8H ;Define the RD port data register address

PORTC EQU 7H ;define the address of RC port data register
TRISD EQU 88H ;define the address of RD port direction control register
TRISC EQU 87H ;define the address of RC port direction control register
ADCON1 EQU 9FH ;define the address of ADC module control register 1
;********************
Z EQU 2 ;define the address of 0 status bit
RP0 EQU 5 ;define the address of page select bit RP0
;************************
RS EQU 2 ;LCD register select signal pin is defined at RD.2 pin
RW EQU 1 ;LCD read/write signal pin is defined at RD.1 pin
E EQU 0 ;LCD chip select signal pin is defined at RD.0 pin
COUNT EQU 24H ;define the address of count register
TMP1 EQU 25H ;define the address of temporary register
;**********************
  ORG 000H
  NOP ;place a null operation instruction
  GOTO MAIN
  ORG required by ICD 0008H
;******************************************************
TABLE ;Get the display code of the first line WWW.PICAVR.COM 
  ADDWF PCL,1 ;Address offset plus current PC value
  RETLW 20H ;Space
  RETLW 57H ;W
  RETLW 57H ;W
  RETLW 57H ;W
  RETLW 2EH ;.

  RETLW 50H ;P
  RETLW 49H ;I
  RETLW 43H ;C
  RETLW 41H ;A
  RETLW 56H ;V
  RETLW 52H ;R

  RETLW 2EH ;.
  RETLW 43H ;C
  RETLW 4FH ;O
  RETLW 4DH ;M
  RETLW 20H ;SpaceRETLW
  00H
;-------------------- ----------------------------------
TABLE1 ;Get the display code of the second lineTEL:020-86307727
  ADDWF PCL,1 ;Address offset plus current PC valueRETLW                                                  
  54H ;T 
  RETLW 45H ;E                             
  RETLW 4CH ;L
  RETLW 3AH ;:

  RETLW 30H ;0
  RETLW 32H ;2
  RETLW 30H ;0

  RETLW 0B0H ;-
  RETLW 38H ;8
  RETLW 36H ;6
  RETLW 33H ;3
  RETLW 30H ;0
  RETLW 37H ;7
  RETLW 37H ;7
  RETLW 32H ;2
  RETLW 37H ;7
  RETLW 20H ;space
  RETLW 00H
;******* ************************************************
MAIN

  BSF STATUS,RP0          
  MOV LW 07H
  MOV WF ADCON1 ; Set RA port to normal digital IO port
  MOV LW 00H
  MOV WF TRISD ; Define RD port and RC port to output
  MOV WF TRISC
  BCF STATUS,RP0

  CALL DELAY ;Call delay, LCD reset may not be as fast as PIC when powered on
  MOV LW 01H
  MOV WF PORTC ;Clear screen
  CALL ENABLE
  MOV LW 38H
  MOV WF PORTC ;8-bit 2-line 5x7 dot matrix
  CALL ENABLE
  MOV LW 0FH ;Display, cursor, and blinking turned on
  MOV WF PORTC
  CALL ENABLE
  MOV LW 06H ;Text does not move, cursor automatically moves right
  MOV WF PORTC             
  CALL ENABLE

  MOV LW 80H
  MOV WF PORTC ; Display position
  CALL ENABLE

  CALL WRITE1 ;Call the subroutine to send the first line of numbers "WWW.PICAVR.COM"
  MOV LW 0C0H
  MOV WF PORTC ;The location of the first line       
  CALL ENABLE
  CALL WRITE2 ;Call the subroutine to send the second line of numbers "TEL:020-86307727"
  CALL ENABLE
  GOTO $
  
;************************
WRITE1
  CLRF COUNT ;Send the first line of numbers
WRITE_A
  MOV FW COUNT
  CALL TABLE
  MOV WF TMP1
  CALL WRITE3
  INCF COUNT,1
  MOV FW TMP1
  XORLW 00H
  BTFSS STATUS,Z
  GOTO WRITE_A
  RETLW 0
;****************************
WRITE2 ;Send the second line of numbers
  CLRF COUNT
WRITE2_A
  MOV FW COUNT
  CALL TABLE1
  MOV WF TMP1
  CALL WRITE3
  INCF COUNT,1
  MOV FW TMP1
  XORLW 00H
  BTFSS STATUS,Z
  GOTO WRITE2_A
  RETLW 0
;**************************
WRITE3 ;Send data to LCD subroutine
  MOV WF PORTC
  BSF PORTD,RS
  BCF PORTD,RW
  BCF PORTD,E
  CALL DELAY
  BSF PORTD,E
  RETLW 0
;***********************************************
ENABLE
  BCF PORTD,RS ;Write control command subroutine
  BCF PORTD,RW
  BCF PORTD,E
  CALL DELAY
  BSF PORTD,E
  RETLW 0
;************************************************
DELAY                       
                             ;Subroutine name, also subroutine entry address
       MOV lw 0ffh ;Send the outer loop parameter value FFH through W MOV wf 20h ;to the 20H unit lp0
       used as the outer loop variable
MOV lw 0ffh ; pass the inner loop parameter value FFH through W
       MOV wf 21h ; send it to the 21H unit used as the inner loop variable
lp1 decfsz 21h,1 ; decrement the content of variable 21H, if it is 0, jump to
       goto lp1 ; jump to LP1
       decfsz 20h,1 ; decrement the content of variable 20H, if it is 0, jump
       to goto lp0 ; jump to LP0
       return ; return to the main program
       end ; end of source program