Datasheet

274
SAM9G35 [DATASHEET]
11053E–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 229
“PIO Disable Register” on page 230
“PIO Output Enable Register” on page 232
“PIO Output Disable Register” on page 233
“PIO Input Filter Enable Register” on page 235
“PIO Input Filter Disable Register” on page 236
“PIO Multi-driver Enable Register” on page 246
“PIO Multi-driver Disable Register” on page 247
“PIO Pull Up Disable Register” on page 249
“PIO Pull Up Enable Register” on page 250
“PIO Peripheral ABCD Select Register 1” on page 252
“PIO Peripheral ABCD Select Register 2” on page 253
“PIO Output Write Enable Register” on page 261
“PIO Output Write Disable Register” on page 262
“PIO Pad Pull Down Disable Register” on page 258
“PIO Pad Pull Down Status Register” on page 260
• 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