delay.inc

汽车无钥进入系统设计,基于PIC单片机16F639,包括电路图和源码

#ifndef DELAY_INC
#define DELAY_INC


#define Delay.Returned	Delay.flag,3

	extern Delay.wait_w_x_50us, Delay.flag, Delay.Counter
	extern Delay.start, Delay.Wait
;
;
;	This macro initialises the delay module
;
;
;Delay.Init macro
;	banksel	OPTION_REG
;	MOVLW	b'00000000'		; SET UP FOR TMR0'S PRESCALER VALUE TO 1
;							; (RAPU, bit7) = 0 to enable weak pull-up for PortA also 
;	MOVWF	OPTION_REG		; this is used for Delay loop only
;	endm

;/*
;
;	This macro waits for up to 12 ms.
;	The time has to be a multible of 50us.
;	It is just added to enhance readability of the source code.
;	It calls Delay.wait_w_x_50us with appropriate parameters.
;	This function is intended to run at 8 MHz.
;	If running other speeds, change the Delay.wait_w_x_50us method.
;
;	@param time The value of time
;	@param unit The character corresponding to the unit of time (i.e. 'u', 'm')
;
;	@example
;	banksel PORTB
;	bsf		PORTB,0
;	Delay.waitFor .500, 'u'
;	banksel PORTB
;	bcf		PORTB,0
;	@end-ex
;	@ex-desc This sets Pin RB0 high for approx. 500 us
;
;	@status Tested
;
;	@stacklevel +1
;
;	@registers Delay.Returned
;
;*/


Delay.WaitFor macro time, unit

	if(unit == 'u')
	movlw (time/.50)
	else
		if (unit == 'm')
	movlw ((time*.1000)/.50)
		endif
	endif
	call Delay.wait_w_x_50us

	endm


;Delay.start	macro us			;build as function?	Yes, absolutely
;	banksel	OPTION_REG			;2Cycles	1	;setting prescaler to 1:2
;	clrf	OPTION_REG			;1Cycles	1
;	banksel	TMR0				;2Cycles	1
;	movlw	0xEA				;1Cycles	1	;0x100 - 0x32 (50u) + 0x06 (static offset) + 0x07(Interrupt) + 0x0F (n first cycle)= 0xEA to compenste static Offsets
;	movwf	TMR0				;1Cycles	1
;	bsf		INTCON,T0IE
;	banksel	Delay.Counter		;don't care timer already started
;	movlw	(us/.50)
;	movwf	Delay.Counter
;	banksel	Delay.flag
;	bcf		Delay.Returned
;	nop
;	endm

;Delay.Wait macro
;	banksel	Delay.flag
;	btfss	Delay.Returned
;	goto	$-1				;at least 1 Cycle
;	bcf		INTCON,T0IE
;	endm

;/*
;
;	This macro must be called within the Interrupt routine, to enable the counter.
;	The Counter function is optimized for the following Interrupt routine.
;	If you do changes to that routine you will have to modify counter.start function,
;	to compensate these instructions (or you will loose precision).
;
;	@param w The multiplicator
;
;	@example
;	INT	code	0x04
;		movwf   W_TEMP	        ; Save off current W register contents
;		movf	STATUS,w
;		clrf	STATUS			; Force to page0
;		movwf	STATUS_TEMP									 
;		movf	PCLATH,w
;		movwf	PCLATH_TEMP		; Save PCLATH
;		movf	FSR,w
;		movwf	FSR_TEMP		; Save FSR
;		GOTO	INT_SERV
;		
;		
;	INT_SERV
;	TIMER0_INT
;		btfss	INTCON,T0IE		; Check if PORTA Interrupt Enabled
;		goto	NEXT_INT		; ... No, then continue search
;	
;		btfss	INTCON,T0IF		; Check if TMR0 Interrupt Flag Set
;		goto	NEXT_INT
;	
;		Delay.Isr				; Handles the delay routines
;		
;		; *** If you want to use Timer0 for other Interrupts modify the Delay.start function,
;		; *** to compensate all instructions, you place here.
;		
;		bcf		INTCON,T0IF
;		goto	EndIsr
;	
;		
;		; ***You may place other Interrupt Handlers here***
;		
;		
;	
;	EndIsr
;		clrf	STATUS			;Select Bank0
;		movf	FSR_TEMP,w
;		movwf	FSR				;Restore FSR
;		movf	PCLATH_TEMP,w
;		movwf	PCLATH			;Restore PCLATH
;		movf	STATUS_TEMP,w
;		movwf	STATUS			;Restore STATUS
;		swapf	W_TEMP,f			  
;		swapf	W_TEMP,w		;Restore W without corrupting STATUS bits
;		RETFIE
;	@end-ex
;	@ex-desc 
;
;	@status Tested
;
;	@stacklevel 0
;
;	@registers TMR0
;
;*/
Delay.Isr macro
	banksel	TMR0			;2Cycles	n
	movlw	0xD8			;1Cycle		n	;so set 0x100-0x32+0x02+0x0E=0xDC
	movwf	TMR0			;1Cycle		n
	banksel	Delay.Counter	;2Cycles	1
	decfsz	Delay.Counter	;1Cycle		1
	goto	Delay.Isr.End	;2Cycle		0
	banksel	Delay.flag		;2Cycles	1
	bsf		Delay.Returned	;1Cycle		1
Delay.Isr.End
	endm



#endif