Differential signal skew adjustment method and transmission circuit
AssigneeFujitsu Limited
InventorHisakatsu YAMAGUCHI
Life of this patent
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Abstract
A differential signal skew adjustment method includes: outputting a differential data signal including a first polarity signal and a second polarity signal from a transmission circuit in synchronization with a cycle of a reference clock; adjusting a phase of a detection clock obtained by dividing the reference clock in accordance with a phase of the first polarity signal; and adjusting a phase of the second polarity signal in accordance with an adjusted phase of the detection clock to adjust skew between the first polarity signal and the second polarity signal.
Claims13
A differential signal skew adjustment method comprising:
- outputting a differential data signal including a first polarity signal and a second polarity signal from a transmission circuit in synchronization with a cycle of a reference clock;
- adjusting a phase of a detection clock obtained by dividing the reference clock in accordance with a phase of the first polarity signal;
- and
- adjusting a phase of the second polarity signal in accordance with an adjusted phase of the detection clock to adjust skew between the first polarity signal and the second polarity signal.
A transmission circuit comprising:
- a clock circuit configured to generate a reference clock and a detection clock obtained by dividing the reference clock;
- a multiplexer configured to perform parallel-to-serial conversion to multi-bit data to generate a serial data sequence;
- a differential output circuit configured to generate a differential data signal including a first polarity signal and a second polarity signal from the serial data sequence to output the differential data signal in accordance with a cycle of the reference clock;
- a delay circuit configured to vary an amount of delay of the second polarity signal;
- and
- a skew control circuit configured to control the delay circuit so that skew between the first polarity signal and the second polarity signal is decreased based on the output from the differential output circuit and the detection clock.
Dependencies are inferred from the claim text.