Atmel Evaluation Kit AT91SAM9M10-G45-EK AT91SAM9M10-G45-EK Data Sheet

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SAM9M10 [DATASHEET]

6355F–ATARM–12-Mar-13

– If USART does not operate in SPI Mode (USART_MODE 

≠ 0xE and 0xF):

MSBF = 0: Least Significant Bit is sent/received first.

MSBF = 1: Most Significant Bit is sent/received first.

– If USART operates in SPI Mode (Slave or Master, USART_MODE = 0xE or 0xF):

CPOL = 0: The inactive state value of SPCK is logic level zero.

CPOL = 1: The inactive state value of SPCK is logic level one.

CPOL is used to determine the inactive state value of the serial clock (SPCK). It is used with CPHA to produce the required
clock/data relationship between master and slave devices.

0: CHRL defines character length.

1: 9-bit character length.

0: The USART does not drive the SCK pin.

1: The USART drives the SCK pin if USCLKS does not select the external clock SCK.

0: 16x Oversampling.

1: 8x Oversampling.

0: The NACK is generated.

1: The NACK is not generated.

0: NACK is sent on the ISO line as soon as a parity error occurs in the received character (unless INACK is set).

1: Successive parity errors are counted up to the value specified in the MAX_ITERATION field. These parity errors gener-
ate a NACK on the ISO line. As soon as this value is reached, no additional NACK is sent on the ISO line. The flag
ITERATION is asserted.

0: User defined configuration of command or data sync field depending on SYNC value.

1: The sync field is updated when a character is written into US_THR register.

Defines the maximum number of iterations in mode ISO7816, protocol T= 0.

0: The USART does not filter the receive line.

1: The USART filters the receive line using a three-sample filter (1/16-bit clock) (2 over 3 majority).

0: Manchester Encoder/Decoder are disabled.