Patent attributes
An enhanced quadrature receive serial interface circuit and methods are provided for calibrating the quadrature receive serial interface circuit. A quadrature receive serial interface circuit comprises a first phase rotator and a second phase rotator generating quadrature clocks of identical frequency. Calibration of the quadrature receive serial interface circuit uses a pseudo random bit sequence (PRBS) received by the quadrature receive serial interface circuit. For calibration, one-half of the received PRBS bits are sampled and the phase rotator generating in-phase 0° and 180° clock signals is adjusted to center the data eye for the sampled half of the PRBS bits. Then all data bits (even and odd data bits) of the received PRBS bits are sampled and the phase rotator generating quadrature phase 90° and 270° clock signals is adjusted to center the data eye of all data bits of the PRBS bits to complete calibration.
