Datasheet

679
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
33.7.5 Register Write Protection
To prevent any single software error from corrupting SPI behavior, certain registers in the address space can be
write-protected by setting the WPEN bit in the ”SPI Write Protection Mode Register” (SPI_WPMR).
If a write access to a write-protected register is detected, the WPVS flag in the ”SPI Write Protection Status
Register” (SPI_WPSR) is set and the WPVSRC field indicates the register in which the write access has been
attempted.
The WPVS bit is automatically cleared after reading SPI_WPSR.
The following registers can be write-protected:
 ”SPI Mode Register”
 ”SPI Chip Select Register”