Power management

An apparatus, method and computer program are described. The apparatus includes throttling control circuitry (215) associated with a given processing element (205) for performing a throttling level selection procedure to select a throttling level indicative of an execution rate at which a higher power processing task received by the given processing element is to be issued to the processing circuitry of the given processing element. The apparatus further comprises a power management circuit (220) for performing a power control process to select an operating voltage and/or a clock frequency to be used by a given processing element, where the power management circuit is configured to select the operating voltage and/or the clock frequency according to a throttling level selected for the given processing element; and at least one firmware accessible register (225). The apparatus is configured to control the selection of at least one energy control parameter in accordance with a value read from the at least one r