A voltage regulator is used to regulate the core voltage. The regulator can be configured to balance power consumption, wake-up time from sleep, and maximum clock speed.
The Voltage Regulator Control (SLPCTRL.VREGCTRL) register is used to configure the regulator start-up time and power consumption. The Power Mode Select (PMODE) bit field in SLPCTRL.VREGCTRL can be set to make the regulator switch to Normal mode when OSC32K is the only oscillator enabled and if the device is in sleep mode. In Normal mode, the regulator consumes less power but can supply only a limited amount of current, permitting only a low clock frequency.
The user may select one of the following Voltage Regulator Power modes:
| Voltage Regulator Power Mode | Description | Condition | Active/Idle | Standby/Power-Down |
|---|---|---|---|---|
| Normal (AUTO) | Maximum performance in Active mode and Idle mode | External clock or fast oscillator | Maximum Performance | Low Power |
| 32.768 kHz oscillator | Low Power | Low Power | ||
| Performance (FULL) | Maximum performance in all modes (Active and Sleep) and fast start-up from all sleep modes | Maximum Performance | Maximum Performance |