LCD_data equ P2    ;LCD Data port
LCD_rs   equ P0.2  ;LCD Register Select
LCD_rw   equ P0.1  ;LCD Read/Write
LCD_en   equ P0.0  ;LCD Enable
bitflag  equ 1

ORG 0000H
	JMP init

ORG 0060H

init:    clr   bitflag
         setb  LCD_rs        	;Selected command register
         clr   LCD_rw         ;We are writing in instruction register
         setb  LCD_en        	;Enable H->L

         acall long_delay

lcall LCD_init

LCD_sendstring:
         mov   LCD_data,#80H 	;position cursor
         clr   LCD_rs        	;Selected instruction register
         clr   LCD_en
         acall delay
         setb  LCD_en        	;Enable H->L
         acall delay

         jb    bitflag, nextptr
         mov   dptr, #string1  ;string1 is the label where the string is stored
         sjmp  skip1
nextptr: mov   dptr, #string2  ;string2 is the label where the string is stored

skip1:   cpl   bitflag
         mov   r0, #08h
loop1:   mov   a, r0
         jz    nextadr
         dec   a
         mov   r0, a
         clr   a                 ;clear Accumulator for any previous data
         movc  a,@a+dptr         ;load the first character in accumulator
         jz    here              ;go to exit if zero
         acall lcd_senddata      ;send first char
         inc   dptr              ;increment data pointer
         sjmp  loop1             ;jump back to send the next character
         acall long_delay

nextadr:
         mov   LCD_data,#0C0H    ;Display on, Curson blinking command
         clr   LCD_rs        	   ;Selected instruction register
         clr   LCD_en
         acall delay
         setb  LCD_en        	   ;Enable H->L
         acall delay

loop2:   clr   a                 ;clear Accumulator for any previous data
         movc  a,@a+dptr         ;load the first character in accumulator
         jz    here              ;go to exit if zero
         acall lcd_senddata      ;send first char
         inc   dptr              ;increment data pointer
         sjmp  loop2             ;jump back to send the next character

here:    acall long_delay
         ljmp  LCD_sendstring

string1:
DB   '0123456789abcdef',0h
string2:
DB   ' Sally Test LCD ',0h

LCD_init:
         mov   LCD_data,#0FH 	;Display on, Curson blinking command
         clr   LCD_rs        	;Selected instruction register
         clr   LCD_en
         acall delay
         setb  LCD_en        	;Enable H->L
         acall delay

         mov   LCD_data,#38H 	;Function Set 2-line mode (even for 16x1!)
         clr   LCD_rs        	;Selected instruction register
         clr   LCD_en
         acall delay
         setb  LCD_en        	;Enable H->L
         acall delay
         ret

LCD_senddata:
         mov   LCD_data,A    ;Move the command to LCD port
         setb  LCD_rs        ;Selected data register
         clr   LCD_en
         acall delay
         setb  LCD_en        	;Enable H->L
         acall delay
         ret

delay:
   mov  r2, #01h

wait_0:
   mov  r3, #0FFh   ;reg2 and reg3

wait_1:
   djnz r3, wait_1
   djnz r2, wait_0
   ret

long_delay:
   mov  r2, #03h   ;initialise counters

wait_2:
   mov  r3, #0ffh   ;reg2 and reg3

wait_3:
   mov  r4, #0ffh   ;reg2 and reg3

wait_4:
   djnz r4, wait_4
   djnz r3, wait_3
   djnz r2, wait_2
   ret

end