An apparatus includes a processor and a device. The processor generates an output signal and a control signal. The device consumes power while operating in first and second states. The device consumes less power while in the first state than while in the second state. The processor: accounts for a transition time for the device to transition among a powered off state, the first state, and the second state; and generates the control signal based on the transition time. The device: in response to the control signal, transitions to the second state at a speed of periodicity of a periodic signal of the processor; subsequent to the transitioning to the second state, performs a function based on the output signal; and subsequent to performing the function, transitions from the second state to either the first state or the powered off state.