; uart functions

; default uart settings / 19.2k @ 8 mhz
; ifndef UART_BR_H
.equ	UART_BR_H	= 0
; ifndef UART_BR_L
;.equ	UART_BR_L	= 25
.equ	UART_BR_L	= 8

UART_INIT:

	; baudrate
	ldi tmp1,UART_BR_H
	out UBRRH,tmp1
	ldi tmp1,UART_BR_L
	out UBRRL,tmp1

	; enable
	ldi tmp1,(1<<RXEN)|(1<<TXEN)
	out UCSRB,tmp1

	; frame format -> 8n1
	ldi tmp1,(1<<UCSZ0)|(1<<UCSZ1)
	out UCSRC,tmp1

	ret

UART_INT_RX_INIT:

	in tmp1,UCSRB
	sbr tmp1,(1<<RXCIE)
	out UCSRB,tmp1

	ret

UART_INT_TX_INIT:

	in tmp1,UCSRB
	sbr tmp1,(1<<TXCIE)
	out UCSRB,tmp1

	ret

UART_RX:

	; get/store received byte
	sbis UCSRA,RXC
		rjmp UART_RX
	in uart_rxtx,UDR

	ret

UART_TX:

	; transmit content of uart_rxtx
	sbis UCSRA,UDRE
		rjmp UART_TX
	out UDR,uart_rxtx

	ret