Datasheet

163
ATmega48/88/168 Automotive [DATASHEET]
7530K–AVR–07/14
• Bit 2 – UCSZn2: Character Size n
The UCSZn2 bits combined with the UCSZn1:0 bit in UCSRnC sets the number of data bits (character size) in a frame the
receiver and transmitter use.
• Bit 1 – RXB8n: Receive Data Bit 8 n
RXB8n 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 UDRn.
• Bit 0 – TXB8n: Transmit Data Bit 8 n
TXB8n 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 UDRn.
17.9.4 USART Control and Status Register n C – UCSRnC
• Bits 7:6 – UMSELn1:0 USART Mode Select
These bits select the mode of operation of the USARTn as shown in Table 17-4.
• Bits 5:4 – UPMn1:0: Parity Mode
These bits enable and set type of parity generation and check. If enabled, the transmitter will automatically generate and
send the parity of the transmitted data bits within each frame. The receiver will generate a parity value for the incoming data
and compare it to the UPMn setting. If a mismatch is detected, the UPEn Flag in UCSRnA will be set.
Bit 7 6 543 2 1 0
UMSELn1 UMSELn0 UPMn1 UPMn0 USBSn UCSZn1 UCSZn0 UCPOLn UCSRnC
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value 0 0 0 0 0 1 1 0
Table 17-4. UMSELn Bits Settings
UMSELn1 UMSELn0 Mode
0 0 Asynchronous USART
0 1 Synchronous USART
1 0 (Reserved)
1 1 Master SPI (MSPIM)
(1)
Note: 1. See Section 18. “USART in SPI Mode” on page 168 for full description of the master SPI mode (MSPIM)
operation
Table 17-5. UPMn Bits Settings
UPMn1 UPMn0 Parity Mode
0 0 Disabled
0 1 Reserved
1 0 Enabled, even parity
1 1 Enabled, odd parity