Datasheet
329
SAM4S Series [DATASHEET]
11100F–ATARM–29-Jan-14
18.4.3 Supply Controller Control Register
Name: SUPC_CR
Address: 0x400E1410
Access: Write-only
This register can only be written if the WPEN bit is cleared in the System Controller Write Protection Mode Register (SYSC_MR).
VROFF: Voltage Regulator Off
0 (NO_EFFECT): No effect.
1 (STOP_VREG): If KEY is correct, asserts the vddcore_nreset and stops the voltage regulator.
Note: This bit is located in the VDDIO domain.
XTALSEL: Crystal Oscillator Select
0 (NO_EFFECT): No effect.
1 (CRYSTAL_SEL): If KEY is correct, switches the slow clock on the crystal oscillator output.
Note: This bit is located in the VDDIO domain.
KEY: Password
31 30 29 28 27 26 25 24
KEY
23 22 21 20 19 18 17 16
––––––––
15 14 13 12 11 10 9 8
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76543210
––––XTALSELVROFF––
Value Name Description
0xA5 PASSWD Writing any other value in this field aborts the write operation.