Assembly code for Matrix Keypad (4x3)

Sample code for Matrix Keypad (4x3).
Following code can be using for 8051 and 8052 ICs like: 89c51, 89c52, 89s51, 89s52, 89c2051.

 

;==========================================================
;	Pin Definations
;==========================================================
keypad          equ     90h
key1            equ     90h
key2            equ     91h
key3            equ     92h
key4            equ     93h
key5            equ     94h
key6            equ     95h
key7            equ     96h
;==========================================================
; Main Program starts from here
;==========================================================
loop:           mov a,keypad
                orl a,#7fh
                mov keypad,a

                clr key4

                jb key1,chkkey2
                call debounce
                jb key1,chkkey2
                jnb key1,$
                mov @r0,#01h
                inc r0
                mov lcddatabus,#'1'
                call lcddata
                

chkkey2         jb key2,chkkey3
                call debounce
                jb key2,chkkey3
                jnb key2,$
                mov @r0,#02h
                inc r0
                mov lcddatabus,#'2'
                call lcddata
                

chkkey3         jb key3,chkkey4
                call debounce
                jb key3,chkkey4
                jnb key3,$
                mov @r0,#03h
                inc r0
                mov lcddatabus,#'3'
                call lcddata
                

chkkey4         mov a,keypad
                orl a,#7fh
                mov keypad,a

                clr key5

                jb key1,chkkey5
                call debounce
                jb key1,chkkey5
                jnb key1,$
                mov @r0,#04h
                inc r0
                mov lcddatabus,#'4'
                call lcddata
                

chkkey5         jb key2,chkkey6
                call debounce
                jb key2,chkkey6
                jnb key2,$
                mov @r0,#05h
                inc r0
                mov lcddatabus,#'5'
                call lcddata
                
                                              
chkkey6         jb key3,chkkey7
                call debounce
                jb key3,chkkey7
                jnb key3,$
                mov @r0,#06h
                inc r0
                mov lcddatabus,#'6'
                call lcddata
                

chkkey7         mov a,keypad
                orl a,#7fh
                mov keypad,a

                clr key6

                jb key1,chkkey8 
                call debounce
                jb key1,chkkey8 
                jnb key1,$
                mov @r0,#07h
                inc r0
                mov lcddatabus,#'7'
                call lcddata
                

chkkey8         jb key2,chkkey9
                call debounce
                jb key2,chkkey9 
                jnb key2,$
                mov @r0,#08h
                inc r0
                mov lcddatabus,#'8'
                call lcddata
                
                                              
chkkey9         jb key3,chkkey10
                call debounce
                jb key3,chkkey10
                jnb key3,$
                mov @r0,#09h
                inc r0
                mov lcddatabus,#'9'
                call lcddata
                

chkkey10        mov a,keypad
                orl a,#7fh
                mov keypad,a

                clr key7

                jb key2,chkkey11
                call debounce
                jb key2,chkkey11
                jnb key2,$
                mov @r0,#00h
                inc r0
                mov lcddatabus,#'0'
                call lcddata
                

chkkey11        jb key3,chkkey12
                call debounce
                jb key3,chkkey12
                jnb key3,$
                jmp back_esc
                                              
chkkey12        jb key1,chkkeyend
                call debounce
                jb key1,chkkeyend
                mov dptr,#msgplzwait
                call lcddisp
                call display_dot

                jnb key1,$

                call check_pw_one
                jnb 01h,pwd_two
                jmp correct_pw
;=====================================================
;      	Program ENDS here
;=====================================================
 

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