second.s

我自己编译使用的dspic源代码.简单实用.

	.equ __30F4011, 1
	.include "p30F4011.inc"
 	.global __reset			    ;The label for the first line of code. 
 	.global	__OscillatorFail	;Declare Oscillator Fail trap routine label
 	.global	__AddressError		;Declare Address Error trap routine label
	.global	__StackError		;Declare Stack Error trap routine label
	.global	__MathError		    ;Declare Math Error trap routine label
	.global	Flags
    .global __T1Interrupt    ;Declare Timer 1 ISR name global

	.section .nbss
	.align	2
     Flags:	.space	2
	.equ	Fcy, #7372800
    .equiv	LED1on,	0
	.equiv	LED2on,	1
	.equiv	LED3on,	2
	.equiv	LED0,		0
	.equiv	LED1,		1	;LED1 connected to RE4
	.equiv	LED2,		2	;LED2 connected to RE5	
	.equiv	LED3,		3	;LED2 connected to RE5
	.equiv	LED4,		4
	.equiv	LED5,		5

;Start of code
	.text				;Start of Code section
__reset:    mov	 #__SP_init,w15 ;Initalize the Stack Pointer
	        mov	 #__SPLIM_init,w0
	        mov	 w0,SPLIM	    ;Initialize the Stack Pointer Limit Register
	        nop			        ;Add NOP to follow SPLIM initialization
	        clr	W0		;Initialize Working registers to 0x0000
			mov	W0,W14 ;clr working registers w0 to w14
			repeat	#12
			mov	W0,[++W14]
			clr	W14
;main code
    		clr		Flags					;clear all Flags
			RCALL	Init_PORTS			; Initialize the I/O ports	
			RCALL 	Init_TMR1			;initialize TMR1 for 0.5 sec interrupt
Again:
			nop	
			nop
			bra	Again					;repeat again
;------------------------------------------------------------------------------
Init_PORTS:
	
	clr	LATE
	mov	#0x0,W0				; set RD7 to RD4 as outputs
	mov	W0,TRISE
	return
;------------------------------------------------------------------------------
Init_TMR1:
CLR T1CON ; Stops the Timer1 and reset control reg.
CLR TMR1 ; Clear contents of the timer register
MOV #0x1FFF, w0 ; Load the Period register
MOV w0, PR1 ; with the value 0xFFFF
BSET IPC0, #T1IP0 ; Setup Timer1 interrupt for
BCLR IPC0, #T1IP1 ; desired priority level
BCLR IPC0, #T1IP2 ; (this example assigns level 1 priority)
BCLR IFS0, #T1IF ; Clear the Timer1 interrupt status flag
mov	#0x8020,W0		; Fosc/4, 1:8 prescale, start TMR1 
mov	W0,T1CON
BSET IEC0, #T1IE ; Enable Timer1 interrupts
return
;-----------------------------------------------------------------------------
__T1Interrupt:

			bclr   IFS0, #T1IF			;clr interrupt flag
;			btsc	Flags,#LED1on			; LED1 flags set?
;			bra	ToggleLED1				;yes then toggle LED1
;			bclr	PORTE,#LED1				;no then turn off LED1
;			retfie
;			bra	next
;ToggleLED1:
nop

			btg	PORTE,#LED0
nop
			btg	PORTE,#LED1	
nop		;yes then toggle LED1
			btg	PORTE,#LED2
nop	
		btg	PORTE,#LED3
nop
			btg	PORTE,#LED4
nop
			btg	PORTE,#LED5
nop		
;next:		btsc	Flags,#LED3on			; LED1 flags set?
;			bra	ToggleLED3				;yes then toggle LED1
;			bclr	PORTE,#LED3				;no then turn off LED1
;			bra	NextLED
;ToggleLED3:
;			btg	PORTE,#LED3				;yes then toggle LED1
;NextLED:
 ;			btsc	Flags,#LED2on			; LED1 flags set?
;			bra	ToggleLED2				;yes then toggle LED1
;			bclr	PORTE,#LED2			;no then turn off LED1
;			nop
;			retfie
;ToggleLED2:
;			btg	PORTE,#LED2				;yes then toggle LED1
;			nop
			retfie

.end