Embodiments include a system, an apparatus, a device, and a method. An apparatus includes a synchronous circuit including a first subcircuit powered by a first power plane having a first power plane voltage and a second subcircuit powered by a second power plane having a second power plane voltage. The apparatus also includes an error detector operable to detect an incidence of a computational error occurring in the first subcircuit. The apparatus includes a controller operable to change the first power plane voltage based upon the detected incidence of a computational error. The apparatus also includes a power supply configured to electrically couple with a portable power source and operable to provide a selected one of at least two voltages to the first power plane in response to the controller.