Datasheet

250
SAM9X35 [DATASHEET]
11055E–ATARM–10-Mar-2014
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
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 225
“PIO Disable Register” on page 225
“PIO Output Enable Register” on page 226
“PIO Output Disable Register” on page 227
“PIO Input Filter Enable Register” on page 228
“PIO Input Filter Disable Register” on page 228
“PIO Multi-driver Enable Register” on page 233
“PIO Multi-driver Disable Register” on page 234
“PIO Pull Up Disable Register” on page 235
“PIO Pull Up Enable Register” on page 235
“PIO Peripheral ABCD Select Register 1” on page 237
“PIO Peripheral ABCD Select Register 2” on page 238
“PIO Output Write Enable Register” on page 243
“PIO Output Write Disable Register” on page 243
“PIO Pad Pull Down Disable Register” on page 241
“PIO Pad Pull Down Status Register” on page 242
• 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.
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