AT91SAM9G25-CU Datasheet, PDF (256/1102 Pages) ATMEL Corporation – AT91SAM ARM-based Embbedded MPU

23.7.46 PIO Write Protect Mode Register
Name:
PIO_WPMR
Address: 0xFFFFF4E4 (PIOA), 0xFFFFF6E4 (PIOB), 0xFFFFF8E4 (PIOC), 0xFFFFFAE4 (PIOD)
Access:
Read-write
Reset:
See Table 23-2
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
7
6
5
4
3
2
1
0
–
–
–
–
–
–
–
WPEN
For more information on Write Protection Registers, refer to Section 23.7 ”Parallel Input/Output Controller (PIO) User Interface”.
• WPEN: Write Protect Enable
0: Disables the Write Protect if WPKEY corresponds to 0x50494F (“PIO” in ASCII).
1: Enables the Write Protect if WPKEY corresponds to 0x50494F (“PIO” in ASCII).
Protects the registers:
“PIO Enable Register” on page 231
“PIO Disable Register” on page 231
“PIO Output Enable Register” on page 232
“PIO Output Disable Register” on page 233
“PIO Input Filter Enable Register” on page 234
“PIO Input Filter Disable Register” on page 234
“PIO Multi-driver Enable Register” on page 239
“PIO Multi-driver Disable Register” on page 240
“PIO Pull Up Disable Register” on page 241
“PIO Pull Up Enable Register” on page 241
“PIO Peripheral ABCD Select Register 1” on page 243
“PIO Peripheral ABCD Select Register 2” on page 244
“PIO Output Write Enable Register” on page 249
“PIO Output Write Disable Register” on page 249
“PIO Pad Pull Down Disable Register” on page 247
“PIO Pad Pull Down Status Register” on page 248
• WPKEY: Write Protect KEY
Should be written at value 0x50494F (“PIO” in ASCII). Writing any other value in this field aborts the write operation of the WPEN
bit. Always reads as 0.
SAM9G25 [DATASHEET]
11032C–ATARM–25-Jan-13
256