Program for initialize two row lcd, Assembly Language

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

Posted Date: 3/5/2013 4:26:44 AM | Location : United States







Related Discussions:- Program for initialize two row lcd, Assignment Help, Ask Question on Program for initialize two row lcd, Get Answer, Expert's Help, Program for initialize two row lcd Discussions

Write discussion on Program for initialize two row lcd
Your posts are moderated
Related Questions
Need help with 2 homework assignments

Write a program to do the following: 1. Print your name 2. Using a bottom testing loop, prompt the user to enter a number from 1 to 5.  If the number entered is not 1..5, pri

how i can write a program to divide 2 numbers


I NEED PROJECT OF COFE SHOP

CBW: Convert Signed Byte to Word: This instruction converts a signed byte to a signed word. In other terms, it copies the sign bit of a byte to be converted to all of the bits in

how to write the alp for matrix addition in microprocessor 8086?

Intel's 8237 DMA controller : 1) The 8237 contain 4 independent I/O channels 2) It contains 27 registers, 7 of which are system-wide registers and 5 for each channel. 3)

1) Write an 80x86 assembly language program in EXE file format to do the following tasks: a) Open and read the contents of a file into memory (use at least 1 kB). b) Sort the li

Write an assembly program that adds the elements in the odd indices of the following array. Use LOOP. What is the final value in the register?