Programing assembly with 8051 LCD and button

ORG 0000H                ; Execution starts here


LOOP:SETB P0.3                ; Make port P0.3 as input port
       MOV C,P0.3        ; Get the button state to carry bit
       MOV P1.6,C        ; Display button state on LED
       SJMP LOOP                ; do it continuously
       END

       ORG 0000H                ; Execution starts here
LOOP:SETB P0.3                ; Make port P0.3 as input port
       MOV C,P0.3        ; Get the button state to carry bit
       JC LOOP                ; check if button is pressed
       CPL P1.6                ; if pressed compliment the port
       JNB P0.3,$        ; Wait until the button is released
       SJMP LOOP                ; do it continuously
       END

#include <sfr51.inc>
; pin p0.0 is  mode  button
; pin p0.1 is  exit button
; pin p1 -> data 
; pin p2.0 -> rs pin
; pin p2.1 -> r/w pin
; pin p2.2 > enable pin-

Flag		BIT   PSW.1   ; genearl purpose bit ..

		ORG   0000H

Main:		clr   Flag

Test_But:
		jnb 		p0.0, Test_But
		acall 	Delay_20
		jnb		p0.0, Test_But

		jb		Flag, Next1
		acall		Display1
		setb		Flag	; next time - goto display2 ..

		sjmp		But_Rel
		
Next1:
		acall		Display2
		clr		Flag

But_Rel:
		jb		p0.0, But_Rel; check if button is released ..
		sjmp		Test_But
	
; = = s u b s = = = =

send:		MOV	P1,A
		CLR	P2.0
		CLR	P2.1
		SETB	P2.2
		CLR	P2.2
		RET

; = = = = = =

display:	MOV	P1,A
		SETB	P2.0
		CLR	P2.1
		SETB	P2.2
		CLR	P2.2
		RET

; = = = = = =

initlcd: 	mov 	a,#38h
            acall send
            acall delay
            mov 	a,#0Eh 
            acall send
            acall delay
            mov 	a,#01h 
            acall send
            acall delay
            ret

; = = = = = =

display1:	acall	initlcd
		mov	a,#'M'
		acall display
		acall delay
		mov	a,#'O'
		acall	display
		acall delay
		mov	a,#'D'
		acall	display
		acall	delay
		mov	a,#'E'
		acall display
		acall delay
		mov	a,#'2'
 		acall display
		acall delay
		ret

; = = = = = =

display2:	acall initlcd
		mov	a,#'M'
		acall display
		acall delay
		mov	a,#'O'
		acall display
		acall delay
		mov	a,#'D'
		acall display
		acall delay
		mov	a,#'E'
		acall display
		acall delay
		mov	a,#'1'
		acall display
		acall delay
		ret

; = = = = = =

delay:	MOV	R3,#100

HERE1:  	MOV 	R4,#255
HERE2:  	DJNZ	R4,HERE2
		DJNZ	R3,HERE1
		RET

;----------------------20ms delay---------------------------------------

Delay_20:		PUSH		00h
			PUSH		01h
			MOV		R0, #30
Delay_20_Loop1:	MOV		R1, #255
Delay_20_Loop2:	DJNZ		R1, Delay_20_Loop2
			DJNZ		R0, Delay_20_Loop1 
			POP		01h
			POP		00h
			RET

END