AT90PWM216-16SE ATMEL [ATMEL Corporation], AT90PWM216-16SE Datasheet - Page 206

• Manufacturer Part Number: AT90PWM216-16SE
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable flash
• Manufacturer: ATMEL [ATMEL Corporation]

18.10.4
206
AT90PWM216/316
USART Control and Status Register C – UCSRC
• Bit 4 – RXEN: Receiver Enable
Writing this bit to one enables the USART Receiver. The Receiver will override normal port oper-
ation for the RxD pin when enabled. Disabling the Receiver will flush the receive buffer
invalidating the FE, DOR, and UPE Flags.
This bit is available for both USART and EUSART mode.
• Bit 3 – TXEN: Transmitter Enable
Writing this bit to one enables the USART Transmitter. The Transmitter will override normal port
operation for the TxDn pin when enabled. The disabling of the Transmitter (writing TXEN to
zero) will not become effective until ongoing and pending transmissions are completed, i.e.,
when the Transmit Shift Register and Transmit Buffer Register do not contain data to be trans-
mitted. When disabled, the Transmitter will no longer override the TxDn port.
This bit is available for both USART and EUSART mode.
• Bit 2 – UCSZ2: Character Size
The UCSZ2 bits combined with the UCSZ1:0 bit in UCSRC sets the number of data bits (Char-
acter SiZe) in a frame the Receiver and Transmitter use.
This bit have no effect when the EUSART mode is enabled.
• Bit 1 – RXB8: Receive Data Bit 8
RXB8 is the ninth data bit of the received character when operating with serial frames with nine
data bits. Must be read before reading the low bits from UDR.
When the EUSART mode is enable and configured in 17 bits receive mode, this bit contains the
seventeenth bit (see EUSART section).
• Bit 0 – TXB8: Transmit Data Bit 8
TXB8 is the ninth data bit in the character to be transmitted when operating with serial frames
with nine data bits. Must be written before writing the low bits to UDR.
When the EUSART mode is enable and configured in 17 bits transmit mode, this bit contains the
seventeenth bit (See EUSART section).
• Bit 7 – Reserved Bit
This bit is reserved for future use. For compatibilty with future devices, this bit must be written to
zero when USCRC is written.
• Bit 6 – UMSEL: USART Mode Select
This bit selects between asynchronous and synchronous mode of operation.
Bit
Read/Write
Initial Value
R/W
7
0
-
UMSEL0
R/W
6
0
UPM1
R/W
5
0
UPM0
R/W
4
0
USBS
R/W
3
0
UCSZ1
R/W
2
1
UCSZ0
R/W
1
1
UCPOL
R/W
0
0
7710D–AVR–08/09
UCSRC