Atmel SAM4S-XPLD Atmel ATSAM4S-XPLD ATSAM4S-XPLD Hoja De Datos

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SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13

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).

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.

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