ATmega88PA Automotive Atmel Corporation, ATmega88PA Automotive Datasheet - Page 211

• Manufacturer Part Number: ATmega88PA Automotive
• Manufacturer: Atmel Corporation

21.8.5
9223B–AVR–09/11
USART MSPIM Baud Rate Registers – UBRRnL and UBRRnH
• Bit 5:3 – Reserved Bits in MSPI mode
When in MSPI mode, these bits are reserved for future use. For compatibility with future
devices, these bits must be written to zero when UCSRnC is written.
• Bit 2 – UDORDn: Data Order
When set to one the LSB of the data word is transmitted first. When set to zero the MSB of the
data word is transmitted first. Refer to the Frame Formats section page 4 for details.
• Bit 1 – UCPHAn: Clock Phase
The UCPHAn bit setting determine if data is sampled on the leasing edge (first) or tailing (last)
edge of XCKn. Refer to the SPI Data Modes and Timing section page 4 for details.
• Bit 0 – UCPOLn: Clock Polarity
The UCPOLn bit sets the polarity of the XCKn clock. The combination of the UCPOLn and
UCPHAn bit settings determine the timing of the data transfer. Refer to the SPI Data Modes
and Timing section page 4 for details.
The function and bit description of the baud rate registers in MSPI mode is identical to normal
USART operation. See “UBRRnL and UBRRnH – USART Baud Rate Registers” on page 201.
Atmel ATmega48PA/88PA/168PA [Preliminary]
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