Datasheet

495
SAM4S [DATASHEET]
11100E–ATARM–24-Jul-13
28.2.16.21PMC Write Protect Mode Register
Name: PMC_WPMR
Address: 0x400E04E4
Access: Read-write
Reset: See Table 28-3
• 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 Start-up Mode Register”
• “PMC Fast Start-up Polarity Register”
• “PMC Peripheral Clock Enable Register 1”
• “PMC Peripheral Clock Disable Register 1”
• “PMC Oscillator Calibration Register”
• WPKEY: Write Protect KEY
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
Value Name Description
0x504D43 PASSWD
Writing any other value in this field aborts the write operation of the WPEN
bit. Always reads as 0.