US Patent 11868173 Wireline transceiver with internal and external clock generation

An integrated circuit device having functional circuitry driven by a clock signal includes onboard clock generation circuitry. The clock generation circuitry includes an input configured to accept a frequency reference signal, at least one variable loading capacitor coupled to the input for converting the crystal resonator signal into a calibrated clock signal, and calibration circuitry configured to calibrate the at least one variable loading capacitor based on a reference voltage. The input configured to accept a frequency reference signal may be configured to accept a crystal resonator signal.