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

Seg-segment-assemblers directive-microprocessor, SEG : Segment of a Label:...

SEG : Segment of a Label:- The SEG operator is which is used to decide the segment address of the, variable, label or procedure and substitutes the segment base address in plac

Shl/sal-logical instruction-microprocessor, SHL/SAL : Shift logical/Arithm...

SHL/SAL : Shift logical/Arithmetic Left: These instructions shift the operand byte or word bit by bit to the left and insert 0 in the newly introduced least significant bits. In c

FIRE ALARM PROGRAMMING, PLEASE MAY YOU ASSIST ME WITH SAMPLE CODES FOR PROG...

PLEASE MAY YOU ASSIST ME WITH SAMPLE CODES FOR PROGRAMING A FIRE ALARM MINI PROJECT

Segment registers-microprocessor, Segment Registers The 8086 addresses ...

Segment Registers The 8086 addresses a segmented memory unlike 8085. The complete 1 megabyte memory, which 8086 is capable to address is divided into 16 logical segments.Thusea

8086 assembly language program, move a byte string ,16 bytes long from the ...

move a byte string ,16 bytes long from the offset 0200H to 0300H in the segment 7000H

Conditional branch instruction-microprocessor, Conditional branch Instructi...

Conditional branch Instruction When these type of instructions are executed, they transfer control of execution to the address mention relatively in the instruction, provided t

#title.Statement of the Problem., Can you write for me an essay, topic is: ...

Can you write for me an essay, topic is: Statement of the Problem. Length: 270 words. I will send you the Formula for the Problem Statement on your Email attachment. Do you agree?

Program to find the largest number in an array, Write a MC68H12 assembly la...

Write a MC68H12 assembly language program to find the largest number in an array of ten 8-bit numbers. The array is stored in memory locations starting at address $1100. Use branch

Prepare the assembly code sequence, Problem (a) Prepare the assembly c...

Problem (a) Prepare the assembly code sequence for each of the four styles (accumulator, memory-memory, stack, load/store) of machine for the code fragment: A = B + C;

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