ATMEGA16-16AU SL602 Atmel, ATMEGA16-16AU SL602 Datasheet - Page 153

• Manufacturer Part Number: ATMEGA16-16AU SL602
• Manufacturer: Atmel

Parity Generator
Disabling the
Transmitter
2466T–AVR–07/10
The Transmit Complete (TXC) Flag bit is set one when the entire frame in the transmit Shift
Register has been shifted out and there are no new data currently present in the transmit buffer.
The TXC Flag bit is automatically cleared when a transmit complete interrupt is executed, or it
can be cleared by writing a one to its bit location. The TXC Flag is useful in half-duplex
communication interfaces (like the RS485 standard), where a transmitting application must enter
receive mode and free the communication bus immediately after completing the transmission.
When the Transmit Compete Interrupt Enable (TXCIE) bit in UCSRB is set, the USART Transmit
Complete Interrupt will be executed when the TXC Flag becomes set (provided that global inter-
rupts are enabled). When the transmit complete interrupt is used, the interrupt handling routine
does not have to clear the TXC Flag, this is done automatically when the interrupt is executed.
The parity generator calculates the parity bit for the serial frame data. When parity bit is enabled
(UPM1 = 1), the transmitter control logic inserts the parity bit between the last data bit and the
first stop bit of the frame that is sent.
The disabling of the transmitter (setting the TXEN to zero) will not become effective until ongoing
and pending transmissions are completed, that is, when the transmit Shift Register and transmit
Buffer Register do not contain data to be transmitted. When disabled, the transmitter will no lon-
ger override the TxD pin.
ATmega16(L)
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