.def tempreg=r16
.def counterreg=r17
.def outputreg=r22

.equ DIR_PORTA_MASK=0xA8
.equ DIR_PORTB_MASK=0x02
.equ KEY_INTERRUPT_MASK=0x04


.org 0x0
	rjmp RESET

.org PORTB_INT0_vect
	rjmp ISR 

.org INT_VECTORS_SIZE

RESET:
	; init section 
	; init counter variable 
	ser outputreg

	; initialize 32Mhz clock 
	call SET_CLOCK_32MHZ
	call INIT_INTR
 
	; init PORTs
	; init PORTA (LEDs)
	ldi tempreg,DIR_PORTA_MASK
	sts PORTA_DIR,tempreg

	; init PORTB
	ldi tempreg,DIR_PORTB_MASK
	sts PORTB_DIR,tempreg

	; set pull up resitors for PORTB
	ldi tempreg,PORT_OPC_PULLUP_gc | PORT_ISC_FALLING_gc
	sts PORTB_PIN0CTRL,tempreg
	sts PORTB_PIN2CTRL,tempreg

	; init LEDs
	ser tempreg 
	sts PORTA_OUT,tempreg
	sts PORTB_OUT,tempreg

	; global interrupt flag
	sei

MAIN:
	call READKEYS
	rjmp MAIN

READKEYS:
	; check if keys are pressed
	lds tempreg,PORTB_IN
	
	; is SW1 pressed?
	sbrs tempreg,2
	call SW1_PROC
	
	; is SW2 pressed
	sbrs tempreg,0
	call SW2_PROC
	ret
	
INIT_INTR:
	; activate port interrupt
	ldi tempreg,PORT_INT0LVL_LO_gc
	sts PORTB_INTCTRL,tempreg

	; select pin2
	ldi tempreg,KEY_INTERRUPT_MASK
	sts PORTB_INT0MASK,tempreg

	; set PMIC
	ldi tempreg,PMIC_LOLVLEN_bm
	sts PMIC_CTRL,tempreg

	ret