28.4.5 Advanced Features

Sleepwalking

SleepWalking is the capability for a device to temporarily wake up clocks for a peripheral to perform a task without waking up the CPU from Standby sleep mode. At the end of the sleepwalking task, the device can either be awakened by an interrupt (from a peripheral involved in SleepWalking) or enter again into Standby sleep mode.

In Standby when Sleepwalking is ongoing:

  • All the power domains are turned ON including PDRAM power domain
  • Low power mode of the regulators is not activated during sleepwalking

Wake-Up Time

As shown in the following figure, total wake-up time depends on:

  • Latency due to Reference and Regulator effect.
  • Latency due to Power Domain Gating:

    Usually, wake-up time is measured with the assumption that the power domains are already in active state. When using Power Domain Gating, changing a power domain from OFF to active state will take a certain time, refer to Electrical Characteristics. If all power domains were already in active state in standby sleep mode, this latency is zero.

  • Latency due to the CPU clock source wake-up time.
  • Latency due to the NVM wake-up time from deep power down mode.
Figure 28-2. Total Wake-Up Time from Standby Sleep Mode