Datasheet

357
SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
22.6 Write Protection Registers
To prevent any single software error that may corrupt the DMAC behavior, the DMAC address space can be write-
protected by setting the WPEN bit in the “DMAC Write Protect Mode Register” (DMAC_WPMR).
If a write access to anywhere in the DMAC address space is detected, then the WPVS flag in the DMAC Write
Protect Status Register (MCI_WPSR) is set, and the WPVSRC field indicates in which register the write access
has been attempted.
The WPVS flag is reset by writing the DMAC Write Protect Mode Register (DMAC_WPMR) with the appropriate
access key, WPKEY.
The protected registers are:
 “DMAC Global Configuration Register” on page 359
 “DMAC Enable Register” on page 360
 “DMAC Channel x [x = 0..5] Source Address Register” on page 371
 “DMAC Channel x [x = 0..5] Destination Address Register” on page 372
 “DMAC Channel x [x = 0..5] Descriptor Address Register” on page 373
 “DMAC Channel x [x = 0..5] Control A Register” on page 374
 “DMAC Channel x [x = 0..5] Control B Register” on page 376
 “DMAC Channel x [x = 0..5] Configuration Register” on page 378