Datasheet

729
SAM4E [DATASHEET]
Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14
34.5.16 Register Write Protection
To prevent any single software error from corrupting PIO behavior, certain registers in the address space can be
write-protected by setting the WPEN bit in the PIO Write Protection Mode Register (PIO_WPMR).
If a write access to a write-protected register is detected, the WPVS flag in the PIO Write Protection Status
Register (PIO_WPSR) is set and the field WPVSRC indicates the register in which the write access has been
attempted.
The WPVS bit is automatically cleared after reading the PIO_WPSR.
The following registers can be write-protected:
 PIO Enable Register
 PIO Disable Register
 PIO Output Enable Register
 PIO Output Disable Register
 PIO Input Filter Enable Register
 PIO Input Filter Disable Register
 PIO Multi-driver Enable Register
 PIO Multi-driver Disable Register
 PIO Pull-Up Disable Register
 PIO Pull-Up Enable Register
 PIO Peripheral ABCD Select Register 1
 PIO Peripheral ABCD Select Register 2
 PIO Output Write Enable Register
 PIO Output Write Disable Register
 PIO Pad Pull-Down Disable Register
 PIO Pad Pull-Down Status Register
 PIO Parallel Capture Mode Register