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diff --git a/led_plex/uart.asm b/led_plex/uart.asm
new file mode 100644
index 0000000..e7a5830
--- /dev/null
+++ b/led_plex/uart.asm
@@ -0,0 +1,60 @@
+; 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
+
+UART_INIT:
+
+	; baudrate
+	ldi tmp1,UART_BR_H
+	sts UBRR0H,tmp1
+	ldi tmp1,UART_BR_L
+	out UBRR0L,tmp1
+
+	; enable
+	ldi tmp1,(1<<RXEN)|(1<<TXEN)
+	out UCSR0B,tmp1
+
+	; frame format -> 8n1
+	ldi tmp1,(1<<UCSZ00)|(1<<UCSZ01)
+	sts UCSR0C,tmp1
+
+	ret
+
+UART_INT_RX_INIT:
+
+	in tmp1,UCSR0B
+	sbr tmp1,(1<<RXCIE0)
+	out UCSR0B,tmp1
+
+	ret
+
+UART_INT_TX_INIT:
+
+	in tmp1,UCSR0B
+	sbr tmp1,(1<<TXCIE0)
+	out UCSR0B,tmp1
+
+	ret
+
+UART_RX:
+
+	; get/store received byte
+	sbis UCSR0A,RXC0
+		rjmp UART_RX
+	in uart_rxtx,UDR0
+
+	ret
+
+UART_TX:
+
+	; transmit content of uart_rxtx
+	sbis UCSR0A,UDRE
+		rjmp UART_TX
+	out UDR0,uart_rxtx
+
+	ret
+