Datasheet

467
SAM9M10 [DATASHEET]
6355FATARM12-Mar-13
30.6.31 PIO Write Protect Mode Register
Name: PIO_WPMR
Addresses: 0xFFFFF2E4 (PIOA), 0xFFFFF4E4 (PIOB), 0xFFFFF6E4 (PIOC), 0xFFFFF8E4 (PIOD),
0xFFFFFAE4 (PIOE)
Access: Read-write
Reset Value: See Table 30-2
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 listed below:
“PIO Enable Register” on page 451
“PIO Disable Register” on page 451
“PIO Output Enable Register” on page 452
“PIO Output Disable Register” on page 453
“PIO Input Filter Enable Register” on page 454
“PIO Input Filter Disable Register” on page 454
“PIO Set Output Data Register” on page 455
“PIO Clear Output Data Register” on page 456
“PIO Multi-driver Enable Register” on page 459
“PIO Multi-driver Disable Register” on page 460
“PIO Pull Up Disable Register” on page 461
“PIO Pull Up Enable Register” on page 461
“PIO Peripheral A Select Register” on page 462
“PIO Peripheral B Select Register” on page 463
“PIO Output Write Enable Register” on page 464
“PIO Output Write Disable Register” on page 464
WPKEY: Write Protect KEY
Should be written at value 0x534D43 (“SMC” 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