Atmel SAM4SD32B Preliminary Data Sheet page 521

27.2.16.21 PMC Write Protect Mode Register
Name: PMC_WPMR
Address: 0x400E04E4
Access: Read-write
Reset: See Table 27-3
31 30
23 22
15 14
7 6
– –
• WPEN: Write Protect Enable
0 = Disables the Write Protect if WPKEY corresponds to 0x504D43 ("PMC" in ASCII).
1 = Enables the Write Protect if WPKEY corresponds to 0x504D43 ("PMC" in ASCII).
Protects the registers:
"PMC System Clock Enable Register"
"PMC System Clock Disable Register"
"PMC Peripheral Clock Enable Register 0"
"PMC Peripheral Clock Disable Register 0"
"PMC Clock Generator Main Oscillator Register"
"PMC Clock Generator PLLA Register"
"PMC Clock Generator PLLB Register"
"PMC Master Clock Register"
"PMC USB Clock Register"
"PMC Programmable Clock Register"
"PMC Fast Startup Mode Register"
"PMC Fast Startup Polarity Register"
"PMC Peripheral Clock Enable Register 1"
"PMC Peripheral Clock Disable Register 1"
"PMC Oscillator Calibration Register"
• WPKEY: Write Protect KEY
Should be written at value 0x504D43 ("PMC" in ASCII). Writing any other value in this field aborts the write operation of the
WPEN bit. Always reads as 0.
11100B–ATARM–31-Jul-12
29 28
WPKEY
21 20
WPKEY
13 12
WPKEY
5 4
– –
SAM4S Series [Preliminary]
27 26
19 18
11 10
3 2
– –
25 24
17 16
9 8
1 0
– WPEN
521