Clock Signal Skew Calibration Apparatus and Control Method

A method comprising:

• generating, by a frequency doubler, a clock signal based on a plurality of multi-phase clock signals;
• generating, by a frequency divider, a reduced frequency signal indicative of a skew of a first multi-phase clock signal of the plurality of multi-phase clock signals;
• comparing the reduced frequency signal with a predetermined duty cycle;
• and
• adjusting the skew of the first multi-phase clock signal by generating a control signal to modify a delay applied to the first multi-phase clock signal.

A system comprising:

• a multi-phase clock generator configured to generate a plurality of multi-phase clock signals;
• a plurality of delay lines configured to receive the plurality of multi-phase clock signals;
• and
• a clock skew calibration circuit coupled to the multi-phase clock generator through the plurality of delay lines, wherein a first clock skew calibration unit of the clock skew calibration circuit comprises a frequency doubler, a frequency divider and a delay line control circuit configured to adjust a skew of a first multi-phase clock signal by modifying a delay applied to the first multi-phase clock signal based on a duty cycle comparison.