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Arm Cortex-A55 Core Technical Reference Manual : Architectural clock gating modes

Architectural clock gating modes

When the Cortex®-A55 core is in standby mode, it is architecturally clock gated at the top of the clock tree.

Wait for Interrupt (WFI) and Wait for Event (WFE) are features of Arm®v8‑A architecture that put the core in a low-power standby mode by architecturally disabling the clock at the top of the clock tree. The core is fully powered and retains all the state in standby mode.