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

Add-arithmetic instruction-microprocessor, ADD:  Add :- This instruction ...

ADD:  Add :- This instruction adds an immediate contents of a memory location specified in the a register ( source ) or instruction to the contents of another register (destinat

Hand shaking-microprocessor, Hand shaking : Handshaking, or 2-way hand...

Hand shaking : Handshaking, or 2-way handshaking, is 1 type of strobe operation. It typically involves 2 handshaking lines: an output line to denote when the board is ready an

Inc-arithmetic instruction-microprocessor, INC: Increment : - This instruct...

INC: Increment : - This instruction increments the contents of the particular memory or register location by the value 1. All the condition code flags are affected except the carry

Computer organization, write a program using assembly language that print y...

write a program using assembly language that print your name

maximim and minimum mode 8088-microprocessor, Maximim and Minimum mode 808...

Maximim and Minimum mode 8088 system : In the maximum mode, the pin 880 is lastingly high. The functions and timings of other pins of 8088 are exactly similar to 8086. Due to t

Program for declare the threshold, 1. Start your program at address $8500. ...

1. Start your program at address $8500. To do this you need to inform the assembler, through the EQU and ORG assembler directives, that you want your program to start at $8500. Thi

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;

Call-unconditional branch instruction-microprocessor, CALL : Unconditional...

CALL : Unconditional Call:- This instruction is utilized to call a subroutine from a basic program. In case of assembly language programming, the term procedure is utilized int

Write a mips program that reads a string from user input, Description Wr...

Description Write a MIPS program that reads a string from user input, reverse each word (defined as a sequence of English alphabetic letters or numeric digits without any punctu

Find out the content of program, a- Trace the following program fragment an...

a- Trace the following program fragment and find out the content of ax after the          the execution of the program.         X db   5,7  -3,-9,4,-7,9               Mov

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