Millimeter-scale GaN single crystals in filamentary form, also known as GaN whiskers, grown from solution and a process for preparing the same at moderate temperatures and near atmospheric pressures are provided. Whether the frame contains more than a predetermined number of bytes is determined. The offset cancellation circuitry is operable during a calibration mode to generate an offset cancellation signal when the first and second outputs are both coupled to a voltage between the first supply rail and the second supply rail.