at91rm3400 ATMEL Corporation, at91rm3400 Datasheet - Page 237

• Manufacturer Part Number: at91rm3400
• Description: Atmel Advanced At91 Arm Microcontroller
• Manufacturer: ATMEL Corporation

SPI Slave Mode
1790A–ATARM–11/03
In Slave Mode, the SPI waits for NSS to go active low before receiving the serial clock from an
external master.
In Slave Mode, CPOL, NCPHA and BITS fields of SPI_CSR0 are used to define the transfer
characteristics. The other Chip Select Registers are not used in Slave Mode.
In Slave Mode, the low and high pulse durations of the input clock on SPCK must be longer
than two Master Clock periods.
Figure 76. Slave Mode Block Diagram
SPCK
SPIDIS
NSS
MOSI
SPIEN
S
R
Q
LSB
SPI_RDR
SPI_TDR
Serializer
RD
TD
MSB
SPI_IMR
SPI_IDR
SPI_IER
SPI_SR
S
P
E
N
S
I
D
R
E
T
AT91RM3400
R
D
R
F
O
V
R
E
SPI Interrupt
MISO
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