Datasheet

Bit 2 – PE Parity Error

This bit is set if the next character in the receive buffer had a Parity Error when received and the parity

checking was enabled at that point (UPM1 = 1). This bit is valid until the receive buffer (UDR) is read.

Always set this bit to zero when writing to UCSRA.

Bit 1 – U2X Double the USART Transmission Speed

This bit only has effect for the asynchronous operation. Write this bit to zero when using synchronous

operation.

Writing this bit to one will reduce the divisor of the baud rate divider from 16 to 8 effectively doubling the

transfer rate for asynchronous communication.

Bit 0 – MPCM Multi-processor Communication Mode

This bit enables the Multi-processor Communication mode. When the MPCM bit is written to one, all the

incoming frames received by the USART Receiver that do not contain address information will be

ignored. The Transmitter is unaffected by the MPCM setting. For more detailed information see Multi-

processor Communication Mode.

AVR 8-Bit Microcontroller

USART - Universal Synchronous and Asynchrono...

Datasheet Complete

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