Atmel Evaluation Kit AT91SAM9X25-EK AT91SAM9X25-EK Data Sheet
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Product codes
AT91SAM9X25-EK
673
SAM9X25 [DATASHEET]
11054E–ATARM–10-Mar-2014
Figure 35-11.Slave Mode Functional Bloc Diagram
35.7.5 Write Protected Registers
To prevent any single software error that may corrupt SPI behavior, the registers listed below can be write-protected by
setting the WPEN bit in the SPI Write Protection Mode Register (SPI_WPMR).
setting the WPEN bit in the SPI Write Protection Mode Register (SPI_WPMR).
If a write access in a write-protected register is detected, then the WPVS flag in the SPI Write Protection Status Register
(SPI_WPSR) is set and the field WPVSRC indicates in which register the write access has been attempted.
(SPI_WPSR) is set and the field WPVSRC indicates in which register the write access has been attempted.
The WPVS flag is automatically reset after reading the SPI Write Protection Status Register (SPI_WPSR).
List of the write-protected registers:
Shift Register
SPCK
SPIENS
LSB
MSB
NSS
MOSI
SPI_RDR
RD
SPI
Clock
TDRE
SPI_TDR
TD
RDRF
OVRES
SPI_CSR0
CPOL
NCPHA
BITS
SPIEN
SPIDIS
MISO