AT90PWM216-16SE ATMEL [ATMEL Corporation], AT90PWM216-16SE Datasheet - Page 222

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

19.5.5.1
19.5.5.2
19.6
19.6.1
19.6.2
19.6.2.1
19.6.2.2
222
EUSART Registers Description
AT90PWM216/316
USART I/O Data Register – UDR
EUSART I/O Data Register – EUDR
Parity Checker
OverRun
UDR/EUDR data access with character size up to 8 bits
UDR/EUDR data access with 9 bits per character
All the receiver error flags are valid only when the RxC bit is set and until the UDR register is
read.
The parity checker of the EUSART is available only when data bits are level encoded and
behaves as is USART mode (See Parity checker of the USART).
The Data OverRun (DOR bit of USCRA) flag indicates data loss due to a receiver buffer full con-
dition. This flag operates as in USART mode (See USART section).
• Bit 7:0 – RxB7:0: Receive Data Buffer (read access)
• Bit 7:0 – TxB7:0: Transmit Data Buffer (write access)
This register is common to the USART and EUSART interfaces for Transmit Data Buffer Regis-
ter and Receive Data Buffer Register. See description for UDR register in USART.
• Bit 7:0 – RxB15:8: Receive Data Buffer (read access)
• Bit 7:0 – TxB15:8: Transmit Data Buffer (write access)
This register provide an extension to the UDR register when EUSART is used with more than 8
bits.
When the EUSART is used with 8 or less bits, only the UDR register is used for dta access.
When the EUSART is used with 9 bits character, the behavior is different of the standart USART
mode, the UDR register is used in combinaison with the first bit of EUDR (EUDR:0) for data
access, the RxB8/TxB8 bit is not used.
Initial Value
Initial Value
Read/Write
Read/Write
Bit
Bit
R/W
R/W
7
0
7
0
R/W
R/W
6
0
6
0
R/W
R/W
5
0
5
0
R/W
R/W
4
0
4
0
RXB[15:8]
TXB[15:8]
RXB[7:0]
TXB[7:0]
R/W
R/W
3
0
3
0
R/W
R/W
2
0
2
1
R/W
R/W
1
0
1
0
R/W
R/W
0
0
0
0
7710D–AVR–08/09
EUDR (Read)
EUDR (Write)
UDR (Write)
UDR (Read)