Browsing Archive: July, 2014

Countdown program using assembly language for pic

Posted by Jed Melendres on Saturday, July 26, 2014,

; this program is countdown timer using
; assembly language for pic microcontroller
; upon setting the chosen number
; it will count down automatically

; portB3 for tens switch

; portB2 for ones switch

; portB1 for reset switch

; portB0 for start/pause switch

; portC for the 7 segment display of tens

; portD for the 7 segment display of ones

; pic16f877a

bsf status,5

movlw 1111b

movwf trisb

clrf trisc

clrf trisd

bcf status,5

movlw 0x32

movwf 0x31

again btfsc portb,0

goto again

reset movlw 9

movwf 0x20

...

USING RRF AND RLF

Posted by Jed Melendres on Thursday, July 3, 2014,

; using RLF and RRF
; RRF = rotate bit to the right
; RLF = rotate bit to the left
; simulate using picsimulator ide 8xLED board
; mcu = pic16f84a

; this is a running lights

; set up pins
    bsf status,5
    movlw 0x00
    movwf trisa
    bcf status,5

    movlw 0x32
    movwf 0x21    ; store decimal value 50 to 0x21

;main program
main    movlw 0x01
    movwf porta
    call delay

    rlf porta,1    ; 1 is the destination register (porta)
                     ; for the result of operation
    call delay

    rlf ...
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