20.5.3.6 Regulators, RAMs, and NVM State in Sleep Mode
By default, in Standby mode and Backup mode, the RAMs, NVM, and regulators are automatically set in low-power mode in order to reduce the power consumption:
- The RAM is in low-power mode if the device is in Standby mode.
- Non-Volatile Memory - the NVM is
automatically set in Low-Power mode in these conditions:
- When the device is in Standby mode and the NVM is not accessed. This behavior can be changed by software by configuring the SLEEPPRM bit group of the CTRLB register in the NVMCTRL peripheral.
- When the device is in Idle mode and the NVM is not accessed. This behavior can be changed by software by configuring the SLEEPPRM bit group of the CTRLB register in the NVMCTRL peripheral.
- Regulators: by default, in Standby mode, the PM analyzes the device activity to use either the main or the low-power voltage regulator to supply the VDDCORE.
GCLK clocks, regulators and RAM are not affected in Idle mode and will operate as normal.
| Sleep Mode | SRAM Mode | NVM | Regulators | ||
|---|---|---|---|---|---|
| VDDCORE | VDDBU | ||||
| main | ULP | ||||
| Active | normal | normal | on | on | on |
| Idle | auto(1) | on | on | on | on |
| Standby - case 1 | normal | auto(1) | auto(2) | on | on |
| Standby - case 2 | low power | low power | auto(2) | on | on |
| Standby - case 3 | low power | low power | auto(2) | on | on |
| Standby - case 4 | low power | low power | off | on | on |
| Backup | off | off | off | off | on |
| OFF | off | off | off | off | off |
Note:
- auto: by default, NVM is in low-power mode if not accessed.
- auto: by default, the main voltage regulator is on if GCLK, APBx, or AHBx clock is running during SleepWalking.