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

Memory address decoding-microprocessor, Memory Address Decoding Binary ...

Memory Address Decoding Binary Decoders - Decoders have 2n-inputs and n outputs, each input combination results in a single output line contain a 1, and all other lines contain

Counting Array Values(Programming exercises), Write an application that doe...

Write an application that does the following:(1) fill an array with 50 random integers; (2) loop through the array, displaying each value, and count the number of negative values;

Motorola 68000 series, Motorola 68000 Series : 68000microprocessor is a...

Motorola 68000 Series : 68000microprocessor is a 16 bit processor that has addressing space of 65536 locations, each of which holds a 64-bits word; In order to address those lo

Write a program to find the average of the array , Write a program on the a...

Write a program on the assembly language to do the following: 1- Allocate array with 32bit 100 element 2- Prompt the user to enter the maximum or the upper bound of the rando

4 bit 2s complement multiplier, How to design 4 bit signed 2s complement m...

How to design 4 bit signed 2s complement multiplier?

External system bus architecture-microprocessor, External System Bus Archit...

External System Bus Architecture : This is a 16 bit processor with 40 pins. It has twenty address pins and out of which sixteen are utilized as data pins. This concept of by us

Scanning, how o create the flow chart for scan ROW4, Column 1 and 3.tq

how o create the flow chart for scan ROW4, Column 1 and 3.tq

Write an assembly program to simulate a microwave, 1. The microwave has a c...

1. The microwave has a clock (hh:mm:ss am/pm) and the user should be able to change the clock at any time. 2. For cooking the user should first enter the time. The user can ente

Dec-arithmetic instruction-microprocessor, DEC:  Decrement :- The decremen...

DEC:  Decrement :- The decrement instruction subtracts 1 from the contents of the particular memory location or register. All the conditions code flags except carry flag are affec

Logical instruction-microprocessor, Logical Instruction : This type of...

Logical Instruction : This type of instructions is utilized for carrying out the bit by bit shift, basic logical operations or rotate. All of the condition code flags are affe

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