Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD Data Sheet
Product codes
ATSAM4S-WPIR-RD
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
788
Figure 36-38. SPI Transfer Format (CPHA = 1, 8 bits per transfer)
Figure 36-39. SPI Transfer Format (CPHA = 0, 8 bits per transfer)
36.7.8.4 Receiver and Transmitter Control
36.7.8.5 Character Transmission
The characters are sent by writing in the Transmit Holding register (US_THR). An additional condition for
transmitting a character can be added when the USART is configured in SPI master mode. In the USART_MR, the
value configured on INACK field can prevent any character transmission (even if US_THR has been written) while
6
SCK
(CPOL = 0)
SCK
(CPOL = 1)
MOSI
SPI Master ->TXD
SPI Slave -> RXD
NSS
SPI Master -> RTS
SPI Slave -> CTS
SCK cycle (for reference)
MSB
MSB
LSB
LSB
6
6
5
5
4
4
3
3
2
2
1
1
1
2
3
4
5
7
8
6
MISO
SPI Master ->RXD
SPI Slave -> TXD
SCK
(CPOL = 0)
SCK
(CPOL = 1)
1
2
3
4
5
7
MOSI
SPI Master -> TXD
SPI Slave -> RXD
MISO
SPI Master -> RXD
SPI Slave -> TXD
NSS
SPI Master -> RTS
SPI Slave -> CTS
SCK cycle (for reference)
8
MSB
MSB
LSB
LSB
6
6
5
5
4
4
3
3
1
1
2
2
6