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

Hold response sequence-microprocesssor, Hold Response Sequence The HOLD...

Hold Response Sequence The HOLD pin is examined at leading edge of each clock pulse. If it is received active line by the processor before T4 of the earlier cycle/during the T1

Div-idiv-arithmetic instruction-microprocessor, DIV: Unsigned Division:- T...

DIV: Unsigned Division:- This instruction performs unsigned division operation. It divides an unsigned word or double word by a 16-bit or 8-bit operand. The dividend might be in t

Need algorithm for multiplication in assemby with out mul, need algorithm f...

need algorithm for multiplication in assembly with out mul function?

Interrupt system based on 8259 a-microprocessor, Interrupt System Based on ...

Interrupt System Based on Single 8259 A The 8259A is contained in a 28-pin dual-in-line package that need only a + 5-V supply voltage.  Its organization is shown in given figur

Programming, Using the following table as a guide, write a program that ask...

Using the following table as a guide, write a program that asks the user to enter an integer test score between 0 and 100. The program should display the appropriate letter grade.

Arithmrtic operation exercise assempley HELP!, Open notepad and enter the c...

Open notepad and enter the code for a program that calculates the following arithmetic expression: x = a + b + c - d - e + f The operands a, b, c, d, e, f, and x should be declared

Architecture of 8088-microprocessor, Architecture Of 8088 The register ...

Architecture Of 8088 The register set of 8088 is accurately the same as in to 8086. The architecture of 8088 is also same to 8086 except for 2 changes; a) 8088 has 4-byte instr

Program, Write an application that does the following: (1) fill an array wi...

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;

Calculator, how to add 111 and 333 in assembly language

how to add 111 and 333 in assembly language

Assembly language, how to find out the given number is positive or negative...

how to find out the given number is positive or negative?

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