Program for initialize two row lcd, Assembly Language

Assignment Help:

init_lcd                        ;(this initialises a 2 row lcd)

    bcf     TRISA,0             ;PORTA bit 0 as an output (lcd RS pin)
    bcf     TRISA,1             ;PORTA bit 1 as an output (lcd R/W pin)
    bcf     TRISA,2             ;PORTA bit 2 as an output (lcd E pin)

    
    bcf     lcd_rs
    bcf     lcd_rw
    bcf     lcd_en
    movlw   b'00110000'         ;Instruction - function set. First of 3
    call    lcd_write
    call    Delay5              ;wait MORE THAN 4.1mS


    movlw   b'00110000'         ;Instruction - function set. Second of 3
    call    lcd_write
    movlw   .33                 ;wait MORE THAN 100uS [(33 x 3) +1 +1 + (1 x 2)] - measured 102uS on scope
    movwf   counta              ;1 cycle
    decfsz  counta              ;1 cycle until true then a 2 cycle
    goto    $-2                 ;2 cycle instruction

    movlw   b'00110000'         ;Instruction - function set. Third of 3
    call    lcd_write

    movlw   b'00111000'         ;8 bit data / 2 line display / 5x8 character font
    call    lcd_write
    call    busy

    movlw   b'00001111'         ;instruction bit / display on / cursor position on / blinking cursor on
    call    lcd_write
    call    busy

    movlw   b'00000001'
    call    lcd_write
    call    busy

    movlw   b'00000110'         ;increment cursor position by 1 / don't shift display
    call    lcd_write
    call    busy

    return  ;return from initialization routine

lcd_write

    movwf   lcd_data            ;data to port
    bsf     lcd_en              ;sets LCD enable pin high
    bcf     lcd_en              ;data is latched into lcd on high to low transition of E

    return

busy

    bsf     TRISC,7             ;was output when sending init data, now input to read busy flag
    bsf     lcd_rw              ;set high to read data from lcd
    bsf     lcd_en              ;enable
    btfsc   lcd_busy            ;is the busy flag low?
    goto    $-2                 ;no, go back and keep checking until it is
    bcf     lcd_en              ;busy flag now clear
    bcf     lcd_rw              ;set lcd back to write mode
    bcf     TRISC,7             ;port bit as an output again

    return
Delay30
        movlw   .30             ;delay 30mS
        goto    d0
Delay5
        movlw   .5              ;delay 5ms
d0      movwf   count1
d1      movlw   0xC7
        movwf   counta
        movlw   0x01
        movwf   countb
Delay_0
        decfsz  counta
        goto    $+6
        decfsz  countb
        goto    Delay_0
        decfsz  count1
        goto    d1

        retlw   .0              ;return from the delay routine


Related Discussions:- Program for initialize two row lcd

Assembly language programming, Write an assembly language program that defi...

Write an assembly language program that defines symbolic constants for all seven days of the week

Dq-dt-assemblers directive-microprocessor, DQ:   Define  Quad word:-  Th...

DQ:   Define  Quad word:-  This directive is taken in use to direct the assembler to reserve 4 words (8 bytes) of memory for the specified variable and can initialise it having

Display triangular shape using stars, write an assembly program to display ...

write an assembly program to display triangular star like shape

Input output interface-microprocessor, I/O interface I/O  devices such ...

I/O interface I/O  devices such as displays and keyboards  establish  communication of computer with outside world. Devices may be interfaced in 2 ways Memory mapped I/O and I/

Efficient assembly language program, (1) Write a program that will: (a) dis...

(1) Write a program that will: (a) display "Enter Your Name:" (b) convert the entered name to Capital letters (if small), If any other character is entered, the program wil

Second generation microprocessor, IInd Generation Microprocessor : The ...

IInd Generation Microprocessor : The second generation microprocessor by using n MOS technology seemed in the market in 1973.   The Intel  8080, of nMOS  technology

Assembly assignment help, Problems: 1. Write a single program. Each of th...

Problems: 1. Write a single program. Each of the problems (2-4) should be written within a procedure. Your “main” procedure should call each procedure. Before calling each proc

Code, How to print strings in Right Triangle form?

How to print strings in Right Triangle form?

Interrupt system based on multiple 8259as-microprocessor, Interrupt System ...

Interrupt System Based on Multiple 8259As A multiple 8259A interrupt system is diagrammed in given figure in this figure data bus drivers are not indicated, but they could be i

String manipulation instruction-microprocessor, String Manipulation Instruc...

String Manipulation Instruction A series of words or data bytes are available in memory at consecutive locations, to be mention to individually or collectively, are known as by

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd