Datasheet

514
SAM9N12/SAM9CN11/SAM9CN12 [DATASHEET]
11063K–ATARM–05-Nov-13
32.8.21 DMAC Write Protect Mode Register
Name: DMAC_WPMR
Address: 0xFFFFEDE4
Access: Read-write
Reset: See Table 32-4
• WPEN: Write Protect Enable
0: Disables the Write Protect if WPKEY corresponds to 0x444D41 (“DMA” in ASCII).
1: Enables the Write Protect if WPKEY corresponds to 0x444D41 (“DMA” in ASCII).
Protects the registers:
 “DMAC Global Configuration Register”
 “DMAC Enable Register”
 “DMAC Channel x [x = 0..7] Source Address Register”
 “DMAC Channel x [x = 0..7] Destination Address Register”
 “DMAC Channel x [x = 0..7] Descriptor Address Register”
 “DMAC Channel x [x = 0..7] Control A Register”
 “DMAC Channel x [x = 0..7] Control B Register”
 “DMAC Channel x [x = 0..7] Configuration Register”
• WPKEY: Write Protect KEY
31 30 29 28 27 26 25 24
WPKEY
23 22 21 20 19 18 17 16
WPKEY
15 14 13 12 11 10 9 8
WPKEY
76543210
–––––––WPEN
Value Name Description
0x444D41 PASSWD
Writing any other value in this field aborts the write operation of the WPEN bit.
Always reads as 0.