A method and apparatus for providing telemetry for use in power control functions is disclosed. A system includes an integrated circuit (IC) having a first power management circuit. The IC also includes a number of functional circuit blocks within a number of different power domains. A second power management circuit is implemented external to the IC and includes a number of voltage regulators. Each of the power domains is coupled to receive power from one voltage regulators. During operation, the first power management circuit may send commands requesting the change of one or more voltages provided to the IC. The second power management circuit may respond by performing the requested voltage change(s), and may also provide telemetry data to the first power management circuit. The second power management circuit may also provide telemetry data responsive to receiving a no operation command from the first power management circuit.