單片機(jī)閃爍燈設(shè)計(jì)

;*************************************************
;* 本程序是一個(gè)LED燈的循環(huán)閃爍程序,用INT鍵來切換*
;* 閃爍模式 *www.dangdangdz.com
;*************************************************
include p16f877.inc>
;*----
MODESEL equ 20h
MODESELB equ 21h
Count equ 22h
Count1 equ 23h
Count2 equ 24h
PORTDB equ 25h

;*-----

org 0
goto start
org 4
goto ISR

org 10
start
clrf PORTD ;清D口
movlw 00h
movwf MODESEL ;初始化模式選擇寄存器
movwf MODESELB
movlw b'10010000'
movwf INTCON ;初始化中斷控制
bsf STATUS,RP0
clrf TRISD ;設(shè)D口全為輸出
movlw b'10111111'
OPTION ;選擇INT下降沿有效

bcf STATUS,RP0
call FMsel
movwf PORTDB
movwf PORTD
main btfsc PORTB,0 ;
goto $+6 ;
call Delay ; 按鍵去抖動(dòng)
btfsc PORTB,0
goto $+3 ; /
call FMsel ;/
movwf PORTDB
movf MODESELB,W ;
movwf MODESEL ;
call LongDelay
bcf STATUS,C
rlf PORTDB,1
btfsc STATUS,C
bsf PORTDB,0
movf PORTDB,W
movwf PORTD
goto main

;*----------
Delay ; call指令占用2個(gè)指令周期
clrf Count ; 清 Count占用1個(gè)指令周期
Dloop
decfsz Count,f ; 這兩行指令將延時(shí)
goto Dloop ; (256 * 3) -1 個(gè)指令周期
return ; return占用2個(gè)指令周期

;*----------------
LongDelay
clrf Count
clrf Count1
movlw 0x01
movwf Count2
LDloop
decfsz Count,f
goto LDloop
decfsz Count1,f
goto LDloop
decfsz Count2,f
goto LDloop
return