System and method for adaptively deskewing parallel data signals relative to a clock
AssigneeSilicon Graphics, Inc.
InventorsPhilip Jenkins, Frank Cornett
Life of this patent
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Abstract
A system and method of reducing skew between a plurality of signals transmitted with a transmit clock is described. Skew is detected between the received transmit clock and each of received data signals. Delay is added to the clock or to one or more of the plurality of data signals to compensate for the detected skew. The delay added to each of the plurality of delayed signals is updated to adapt to changes in detected skew.
Claims11
A method of reducing skew between a plurality of signals transmitted with a transmit clock, wherein the plurality of signals includes a first signal and a second signal, the method comprising:
- receiving the transmit clock and each of the plurality of signals;
- detecting skew between the received transmit clock and each of the received signals;
- passing each of the plurality of received signals through a separate delay line, wherein passing each of the plurality of received signals through a separate delay line includes adding delay to one or more of the plurality of received signals to compensate for the detected skew;
- phase comparing each of the plurality of delayed signals to a reference signal to detect changes in the detected skew;
- and
- modifying the delay added to each of the plurality of delayed signals to adapt to changes in the detected skew.
A delay line controller for adding delay to a clock signal and a plurality of data signals, the delay line controller comprising
- a plurality of skew indicator signal inputs, wherein each skew indicator signal input is capable of receiving a skew indicator signal, wherein each skew indicator signal varies as a function of skew between the clock signal and one of the data signals;
- a digital filter connected to each of the plurality of skew indicator signal inputs, wherein each digital filter generates a delay control signal as a function of the skew indicator signal;
- and
- control logic for controlling delay lines as a function of the delay control signals.
Dependencies are inferred from the claim text.