VDDCORE
time
V(PL0)
V(PL2)
VSVSTEP
VSPER
Setting VREG.VSVSTEP to the maximum value allows to transition in one voltage step.
The STATUS.VCORERDY bit is set to '1' as soon as the VDDCORE voltage has reached the target
voltage. During voltage transition, STATUS.VCORERDY will read '0'. The Voltage Ready interrupt
(VCORERDY) can be used to detect a 0-to-1 transition of STATUS.VCORERDY, see also
When entering the standby sleep mode and when no sleepwalking task is requested, the VDDCORE
Voltage scaling control is not used.
23.6.1.5. Sleep Mode Operation
In standby mode, the low power voltage regulator (LPVREG) is used to supply VDDCORE.
When the Run in Standby bit in the VREG register (VREG.RUNSTDBY) is written to '1', VDDCORE is
supplied by the main voltage regulator. Depending on the Standby in PL0 bit in the Voltage Regulator
register (VREG.STDBYPL0), the VDDCORE level is either set to the PL0 voltage level, or remains in the
current performance level.
Table 23-1. VDDCORE Level in Standby Mode
VREG.RUNSTDBY
VREG.STDBYPL0
VDDCORE Supply in Standby Mode
0
-
LPVREG
1
0
MAINVREG in current performance level
(1)
1
1
MAINVREG in PL0
Note:
1.
When the device is in PL0 but VREG.STDBYPL0=0, the MAINVREG is operating in normal power
mode. To minimize power consumption, operate MAINVREG in PL0 mode by selecting
VREG.STDBYPL0=1.
By writing the Low Power mode Efficiency bit in the VREG register (VREG.LPEFF) to '1', the efficiency of
the regulator in LPVREG can be improved when the application uses a limited VDD range (2.5 to 3.6V). It
is also possible to use the BOD33 in order to monitor the VDD and change this LPEFF value on the fly
according to VDD level.
Related Links
on page 191
23.6.2. Voltage Reference System Operation
The reference voltages are generated by a functional block DETREF inside of the SUPC. DETREF is
providing a fixed-voltage source, BANDGAP=1V, and a variable voltage, INTREF.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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