1.5.1 Clock Hierarchy During Standby

When there is no SleepWalking activity occurring:
  1. All GCLK generators with RUNSTDBY = 0 are stopped.
  2. Clock sources with ONDEMAND = 1 enter low-power state.
  3. MCLK and AHB/APB buses are halted.
When a SleepWalking task is triggered:
  1. The peripheral asserts a clock request.
  2. The GCLK controller enables only the required generators.
  3. The requested clock source wakes if in on-demand mode.
  4. Upon task completion, clocks return to their halted state.
Tip: For minimal power consumption during SleepWalking, use low-frequency clock sources (OSCULP32K or XOSC32K) where peripheral timing requirements allow. High-frequency sources (DFLL, FDPLL) require additional regulator activity and increase overall current draw.