ATmega128 datasheet(181/386 Pages) ATMEL

Part #	ATmega128

Description	8-bit Microcontroller with 128K Bytes In-System Programmable Flash

PDF	386 Pages

Scroll/Zoom	100%

Manufacturer	ATMEL [ATMEL Corporation]

Direct Link	http://www.atmel.com

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181 / 386 page

181

2467S–AVR–07/09

ATmega128

The following code example shows a simple USART receive function based on polling of the

Receive Complete (RXC) flag. When using frames with less than eight bits the most significant

bits of the data read from the UDR will be masked to zero. The USART has to be initialized

before the function can be used.

Note:

1. See “About Code Examples” on page 9.

The function simply waits for data to be present in the receive buffer by checking the RXC flag,

before reading the buffer and returning the value.

Assembly Code Example

(1)

USART_Receive:

; Wait for data to be received

sbis

UCSRA, RXC

rjmp

USART_Receive

; Get and return received data from buffer

r16, UDR

ret

C Code Example(1)

unsigned char

USART_Receive( void )

{

/* Wait for data to be received */

while

( !(UCSRA & (1<<RXC)) )

;

/* Get and return received data from buffer */

return

UDR;

}

ATmega128 Datasheet(PDF) 181 Page - ATMEL Corporation