Datasheet

507
SAM9G25 [DATASHEET]
11032C–ATARM–25-Jan-13
31.7.21 DMAC Write Protect Mode Register
Name: DMAC_WPMR
Address: 0xFFFFEDE4 (0), 0xFFFFEFE4 (1)
Access: Read-write
Reset: See Table 31-4
• 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” on page 484
• “DMAC Enable Register” on page 485
• “DMAC Channel x [x = 0..7] Source Address Register” on page 496
• “DMAC Channel x [x = 0..7] Destination Address Register” on page 497
• “DMAC Channel x [x = 0..7] Descriptor Address Register” on page 498
• “DMAC Channel x [x = 0..7] Control A Register” on page 499
• “DMAC Channel x [x = 0..7] Control B Register” on page 501
• “DMAC Channel x [x = 0..7] Configuration Register” on page 503
• “DMAC Channel x [x = 0..7] Source Picture-in-Picture Configuration Register” on page 505
• “DMAC Channel x [x = 0..7] Destination Picture-in-Picture Configuration Register” on page 506
• WPKEY: Write Protect KEY
Should be written at value 0x444D41 (“DMA” in ASCII). Writing any other value in this field aborts the write operation of the
WPEN bit. Always reads as 0.
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