I need to write assembly language.
When i press at keypad i will display at lcd
What microcontroller are you using for your design?
What type of keypad, 3x4, 4x4, etc?
Is this physical hardware or simulation?
BigDog
;In this whole 4-bit tutorial LCD is connected to
;my controller in following way...
;D4 - P3.0
;D5 - P3.1
;D6 - P3.2
;D7 - P3.3
;EN - P3.7
;RS - P3.5
lcd_port equ P3 ;LCD connected to Port3
en equ P3.7 ;Enable connected to P3.7
rs equ P3.5 ;Register select to P3.5
lcd_reset: ;LCD reset sequence
mov lcd_port, #0FFH
mov delay,#20 ;20mS delay
acall delayms
mov lcd_port, #83H ;Data = 30H, EN = 1, First Init
mov lcd_port, #03H ;Data = 30H, EN = 0
mov delay,#15 ;Delay 15mS
acall delayms
mov lcd_port, #83H ;Second Init, Data = 30H, EN = 1
mov lcd_port, #03H ;Data = 30H, EN = 0
mov delay,#5 ;Delay 5mS
acall delayms
mov lcd_port, #83H ;Third Init
mov lcd_port, #03H
mov delay,#5 ;Delay 5mS
acall delayms
mov lcd_port, #82H ;Select Data width (20H for 4bit)
mov lcd_port, #02H ;Data = 20H, EN = 0
mov delay,#5 ;Delay 5mS
acall delayms
ret
lcd_init:
acall lcd_reset ;Call LCD Reset sequence
mov a,#28H ;4-bit, 2 line, 5x7 dots
acall lcd_cmd ;Call LCD command
mov a,#0CH ;Display ON cursor OFF
acall lcd_cmd ;Call LCD command
mov a,#06H ;Set entry mode (Auto increment)
acall lcd_cmd ;Call LCD command
mov a,#80H ;Bring cursor to line 1
acall lcd_cmd ;Call LCD command
ret
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