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

Program on virtual learning environment, Task One Produce a menu such a...

Task One Produce a menu such as the one below (remember to keep to this specification). M E N U 1, Enter Number 1 2, Enter Number 2 3, Display num1 and num2 4, D

Selecting array elements, implement the following c++ code in assembly lang...

implement the following c++ code in assembly language using the block-structured .IF and .while directives

Instructions, Difference between div and idiv

Difference between div and idiv

Type of microprocessor , Type of Microprocessor : Microprocessors fal...

Type of Microprocessor : Microprocessors fall into 3 categories: Single Chip Microcomputers: - Contains RWM, ROM, microprocessor, I/O port, timer and clock. General pu

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

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

Machine level programs-microprocessor, Machine Level Programs In this s...

Machine Level Programs In this section, a few machine levels programming instance, rather then, instruction sequences are presented for comparing the 8086 programming with that

Aaa-arithmetic instruction-microprocessor, AAA: ASCII Adjust after Additio...

AAA: ASCII Adjust after Addition operation the AAA instruction is executed after an ADD instruction that adds 2 ASCII coded operands to give a byte of outcome in the AL. The AAA i

Odd and even numbers, hi, i''m new to assembly language and my teacher told...

hi, i''m new to assembly language and my teacher told us to look for an example of the odd and even numbers program using debug.exe in ms dos as a guide since we just started. plea

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