Atmel SAM4S-EK2 Atmel ATSAM4S-EK2 ATSAM4S-EK2 Data Sheet

Product codes
ATSAM4S-EK2
Page of 1125
 728
SAM4S [DATASHEET]
11100E–ATARM–24-Jul-13
• FCS: Force SPI Chip Select
– Applicable if USART operates in SPI Master Mode (USART_MODE = 0xE):
FCS = 0: No effect.
FCS = 1: Forces the Slave Select Line NSS (RTS pin) to 0, even if USART is no transmitting, in order to address SPI slave
devices supporting the CSAAT Mode (Chip Select Active After Transfer).
• RCS: Release SPI Chip Select
– Applicable if USART operates in SPI Master Mode (USART_MODE = 0xE):
RCS = 0: No effect.
RCS = 1: Releases the Slave Select Line NSS (RTS pin).