System and method for controlling a reset procedure

A system and method are provided for controlling a reset procedure. The system has a plurality of power domains, where each power domain comprises a plurality of components, and a plurality of power controllers, wherein each power controller has at last one associated power domain and is arranged to control a supply of power to each associated power domain. The plurality of power controllers are arranged in a hierarchical arrangement comprising two or more hierarchical levels. A given power controller at a given hierarchical level is arranged to implement a reset procedure requiring a reset to be performed in a given reset domain, where the given reset domain comprises at least a subset of the components provided in multiple power domains associated with multiple power controllers provided in at least one hierarchical level below the given hierarchical level. The given power controller is arranged to initiate a reset procedure by issuing a reset entry request for receipt by each of the multiple power controllers. Each power controller is arranged, on accepting the reset entry request, to perform a reset preparation procedure in respect of each associated power domain within the multiple power domains, and then to issue a response signal to confirm that the reset preparation procedure has been performed. In response to detecting that the response signal has been issued by each of the multiple power controllers, the given power controller asserts a reset signal to the multiple power domains providing components of the given reset domain in order to cause the reset to be performed in a synchronised manner in respect of all of the components in the given reset domain.