i tested my code, it could move data from micro to LCD
now only problem is it could not receive data from keyboard (it does not recognize the pressed switch)

for example:

this subroutine checked the pressed key and it jump to another subroutine when recognize the correspond pressed key:

main:

jnb 90h, button1
jnb 91h, button2
jnb 93h, button3
jnb 92h, main
button1:......
button2:......
button3:......

but it doesnot recognize the pressed key when i pressed, it jump to button1 subrotine at one when never key was pressed.

I change that code to "key state machine" to scan what key was pressed as some example in the net,and used Timer 0 interupt routine to call but it does not work yet.

when i tested i found Timer 0 interrupt even does not occur

The only problem i still face to are it does not recognize data from key board

Moving data from micro to LCD is Ok


The code list here:

;btw, just if you are interesting with usage of timer as debounce/control routine, here is an example how to detect buttons` actions. Here eight buttons are connected to port 1 and controled via timer 0. 

#include "C:RigelReads51includesfr51.inc"

; variables
T0_TEMP	 DATA	0x20		; temporal buffer
T0_STATE DATA	0x21		; unbounced state of buttons
T0_FLAGS DATA	0x22		; button action (bit addressable)
BUTTON8	BIT	T0_FLAGS.7
BUTTON7	BIT	T0_FLAGS.6
BUTTON6	BIT	T0_FLAGS.5
BUTTON5	BIT	T0_FLAGS.4
BUTTON4	BIT	T0_FLAGS.3
BUTTON3	BIT	T0_FLAGS.2
BUTTON2	BIT	T0_FLAGS.1
BUTTON1	BIT	T0_FLAGS.0

; reload value for 50Hz at 11.059Mhz is 11059200/12/50/256 = 72
T0_SCALE EQU	(256-72)

;----------------------------------------------------------------
; reset vectors
	ORG 00H
	LJMP START

	ORG	0BH		; timer 0 ISR
	LJMP	T0_ISR

;----------------------------------------------------------------
; Button control based on Interupt service routine of timer 0
T0_ISR:
	MOV	TH0,#T0_SCALE	; reload timer divider
	PUSH	ACC
	PUSH	PSW
	MOV	A,P1		; load current buttons` state
	XCH	A,T0_TEMP	; keep it
	XRL	A,T0_TEMP	; compare with previous one
	JNZ	T0_ISR_END	; state is changed: debounce...
; two read attemps are with the same result - process it
	MOV	A,T0_TEMP
	XCH	A,T0_STATE	; hold stable state
	XRL	A,T0_STATE	; detect changed bits
	ANL	A,T0_STATE	; detect realised buttons
	ORL	T0_FLAGS,A	; indicate changed buttons
T0_ISR_END:
	POP	PSW
	POP	ACC
	RETI

;----------------------------------------------------------------
; main entrance
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

START:
; set timer 0 to 16-bit mode
	CLR	EA
	MOV	TCON,#00000000b	; stop timer 0
	MOV	TMOD,#00000010b	; timer 0 is 16-bit divider
	MOV	TH0,#T0_SCALE
    
; prepare initial values
	MOV	T0_TEMP,P1
	MOV	T0_STATE,T0_TEMP
	MOV	T0_FLAGS,#00000000b
; run button control
	SETB EA
    SETB ET0
    ;MOV	IE,#10000001b	; allow timer 0 interrupt
	SETB	TR0		; start timer 0
; main cycle: sleep till event occures
RUN:	
	MOV	PCON,#00000001b	; idle mode
	NOP			; some parts require it
	LCALL	BUTTON1_PROCESS
	LCALL	BUTTON2_PROCESS
    LCALL BUTTON3_PROCESS
        LCALL BUTTON4_PROCESS
; the rest calls...
	SJMP	RUN

BUTTON1_PROCESS:
	JNB	BUTTON1,BUTTON1_END 
; button 1 was pressed and realised: process it here
	CLR	BUTTON1
BUTTON1_END:
	RET

BUTTON2_PROCESS:
	JNB	BUTTON2,BUTTON2_END
; button 2 was pressed and realised: process it here
	CLR	BUTTON2
BUTTON2_END:
	RET

; the rest buttons` subroutines
BUTTON3_PROCESS:
	JNB	BUTTON3,BUTTON3_END
; button 2 was pressed and realised: process it here
	CLR	BUTTON3
BUTTON3_END:
	RET

    BUTTON4_PROCESS:
	JNB	BUTTON4,BUTTON4_END
; button 2 was pressed and realised: process it here
	CLR	BUTTON4
BUTTON4_END:
	RET
	END