Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD データシート

803

SAM4S Series [DATASHEET]

Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14

Applicable if USART operates in SPI mode (slave or master, USART_MODE = 0xE or 0xF):
0: The inactive state value of SPCK is logic level zero.
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: The character transmission starts as soon as a character is written into US_THR register (assuming TXRDY was set).
1: The character transmission starts when a character is written and only if RXRDY flag is cleared (Receive Holding Regis-

ter has been read).

0

NORMAL

Normal mode

1

AUTOMATIC

Automatic echo mode. Receiver input is connected to the TXD pin. 

2

LOCAL_LOOPBACK

Local loopback mode. Transmitter output is connected to the Receiver Input.

3

REMOTE_LOOPBACK

Remote loopback mode. RXD pin is internally connected to the TXD pin.