;
; CPU Init module
;
; Initialize all MPU registers and return to calling routine
;
; Trashes R1
;
; Assumes the various .SET symbols have been updated with the 
; appropriate bits needed to initialize the MPU
;
cpu_init:
	ldi	temp, PORTD_INIT	; set output state before direction.
	out	PORTD, temp		; at reset output is low, direction is in.
	ldi	temp, DDRD_INIT
	out	DDRD, temp
	ldi	temp, PORTB_INIT	; ditto
	out	PORTB, temp
	ldi	temp, DDRB_INIT
	out	DDRB, temp

	ldi	temp, ACSR_INIT	; Analog Interrupt Mask
	out	ACSR, temp

	ldi	temp, TCNT0_INIT
	out	TCNT0, temp
	ldi	temp, TCCR0_INIT
	out	TCCR0, temp
	ldi	temp, TIFR_INIT
	out	TIFR, temp
	ldi	temp, TIMSK_INIT	; yeah, this is just a bit set...
	out	TIMSK, temp

	ldi	temp, MCUCR_INIT	; set up sleep mode & Extn interrupt
	out	MCUCR, temp

	ldi	temp, WDTCR_INIT
	out	WDTCR, temp

	ldi	temp, GIMSK_INIT	; External Interrupt mask
	out	GIMSK, temp

	ldi	temp, SREG_INIT
	out	SREG, temp		; enable interrupts

	ret