An integrated circuit, comprising: a plurality of performance sensors configured to measure performance of circuitry of the integrated circuit, wherein at least one of the plurality of performance sensors is connected to each of a plurality of supply domains of the integrated circuit, wherein the integrated circuit comprises a plurality of heterogeneous circuits of different circuit types that have different relationships between supply voltage and circuit speed, and wherein the plurality of performance sensors include sensors adapted to said heterogeneous circuits; and a core power reduction, CPR, controller module (225, 325) coupled to the plurality of performance sensors, wherein the CPR controller module comprises: a sensor interface module configured to communicate with the plurality of performance sensors to collect performance measurements from the plurality of performance sensors by sequentially receiving the performance measurement from each of the plurality of performance sensors; a category identifier/mapping module configured to assign each of the performance measurements to one of a plurality of categories according to the circuit type and the supply domain associated with the corresponding performance measurement; a measurement preprocessing module configured to produce a category performance measurement for each of the plurality of categories; and a CPR processor module configured to process the category performance measurements to determine target voltage levels for each of the plurality of supply domains. a plurality of performance sensors configured to measure performance of circuitry of the integrated circuit, wherein at least one of the plurality of performance sensors is connected to each of a plurality of supply domains of the integrated circuit, wherein the integrated circuit comprises a plurality of heterogeneous circuits of different circuit types that have different relationships between supply voltage and circuit speed, and wherein the plurality of performance sensors include sensors adapted to said heterogeneous circuits; and a core power reduction, CPR, controller module (225, 325) coupled to the plurality of performance sensors, wherein the CPR controller module comprises: a sensor interface module configured to communicate with the plurality of performance sensors to collect performance measurements from the plurality of performance sensors by sequentially receiving the performance measurement from each of the plurality of performance sensors; a category identifier/mapping module configured to assign each of the performance measurements to one of a plurality of categories according to the circuit type and the supply domain associated with the corresponding performance measurement; a measurement preprocessing module configured to produce a category performance measurement for each of the plurality of categories; and a CPR processor module configured to process the category performance measurements to determine target voltage levels for each of the plurality of supply domains. a sensor interface module configured to communicate with the plurality of performance sensors to collect performance measurements from the plurality of performance sensors by sequentially receiving the performance measurement from each of the plurality of performance sensors; a category identifier/mapping module configured to assign each of the performance measurements to one of a plurality of categories according to the circuit type and the supply domain associated with the corresponding performance measurement; a measurement preprocessing module configured to produce a category performance measurement for each of the plurality of categories; and a CPR processor module configured to process the category performance measurements to determine target voltage levels for each of the plurality of supply domains.