SAM4L Datasheet, PDF (605/1185 Pages) ATMEL Corporation – ATSAM ARM-based Flash MCU

ATSAM4L4/L2
ter/slave pair must use the same configuration, and the master must be reconfigured if it is to
communicate with slaves using different configurations. See Figures 24-42 and 24-43.
Table 24-16. SPI Bus Protocol Modes
MR.CPOL
MR.CPHA
0
1
0
0
1
1
1
0
SPI Bus Protocol Mode
0
1
2
3
Figure 24-42. SPI Transfer Format (CPHA=1, 8 bits per transfer)
CLK cycle (for reference)
1
2
3
4
5
6
7
8
CLK
(CPOL= 0)
CLK
(CPOL= 1)
MOSI
SPI Master ->TXD
SPI Slave ->RXD
MISO
SPI Master ->RXD
SPI Slave ->TXD
NSS
SPI Master ->RTS
SPI Slave ->CTS
MSB
6
5
4
3
2
1
LSB
MSB
6
5
4
3
2
1
LSB
Figure 24-43. SPI Transfer Format (CPHA=0, 8 bits per transfer)
CLK cycle (for reference)
1
2
3
4
5
6
7
8
CLK
(CPOL= 0)
CLK
(CPOL= 1)
MOSI
SPI Master -> TXD
SPI Slave -> RXD
MISO
SPI Master -> RXD
SPI Slave -> TXD
NSS
SPI Master -> RTS
SPI Slave -> CTS
42023C–SAM–02/2013
MSB
6
5
4
3
2
1
LSB
MSB
6
5
4
3
2
1
LSB
605