power.asm

代码保护功能处于持续发展中。Microchip 承诺将不断改进产品的代码保护功能。任何试图破坏Microchip 代码保护功能的行为均可视 为违反了《数字器件千年版权法案（Digital Mille

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;
;	Project:	Interfacing PICs
;       Source File:	POWER.ASM		
;	Author:		M. Bates              
;	Date:		20-8-05      
;       .....................................................
;
;	Step through power outputs using button
;	1. DC switch using relay
;	2. Mains AC switch using triac
;	3. Speaker output from relay
;	.....................................................
;       
;       Processor:      PIC 16F877
;
;       Hardware:       Proteus VSM POW1.DSN 
;       Clock:          RC = 100kHz
;       Inputs:         none
;       Outputs:        PortD
;       
;       WDTimer:        Disabled
;       PUTimer:        Enabled
;       Interrupts:     Disabled
;       Code Protect:   Disabled
;
; ***********************************************************

	PROCESSOR 16F877	; Define MCU type
	__CONFIG 0x3733		; Set config fuses (RC clock)

; Register Label Equates.....................................
        
PORTC	EQU	07		; Port C Data Register 
PORTD   EQU     08             	; Port D Data Register  
TRISD	EQU	88		; Port D Direction Register
STATUS	EQU	03		; Carry flag register

; ***********************************************************

; Initialise Port D (Port A defaults to inputs)..............
        
	BANKSEL	TRISD		; Bank 1
       	CLRF	TRISD          	; Outputs
	BANKSEL	PORTD		; Bank 0

; Start main loop ...........................................

start   CLRF    PORTD  		; Clear Port D Data
	BSF	PORTD,3		; Select no output
	BCF	STATUS,0	; Clear carry bit

next	BTFSC	PORTC,0		; Button on?
	GOTO	next		; no
wait	BTFSS	PORTC,0		; yes - off?
	GOTO	wait		; no

	RRF	PORTD		; yes - move bit right
	BTFSS	STATUS,0	; last output?
	GOTO	next		; no - next output
        GOTO   	start          	; yes - restart

        END                   	; terminate source code