Skew compensation method
AssigneeHitachi, Ltd.
InventorsHidehiro Toyoda, Hiroaki Nishi
Life of this patent
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Abstract
In a high-speed serial-to-parallel conversion transmission system, a transmitter inserts pattern data composed of a combination of a plurality of idle characters in a signal to be transmitted such that a receiver measures an amount of skew, while the receiver measures the amount of skew and performs delay control over the received signal. By using the idle characters as the pattern data, a skew compensation pattern can be inserted as invalid data in a transmitted data stream containing valid data.
Claims16
A skew compensation apparatus comprising:
- a transmitter for transmitting a parallel signal to a transmission line unit after converting the parallel signal into a plurality of serial signals;
- and
- a receiver for performing skew compensation for the serial signals received from the transmission line unit,
- said transmitter comprising means for demultiplexing an inputted parallel signal into a plurality of parallel signal groups, means for generating a skew compensation pattern, means for inserting said skew compensation pattern in each of the parallel signal groups outputted from said demultiplexing, means for converting the plurality of parallel signal groups each containing the skew compensation pattern into a plurality of serial signals, and a first interface for transmitting the serial signals to the transmission line unit,
- said receiver comprising a second interface for receiving the serial signals from the transmission line unit, means for demultiplexing the serial signals received by the second interface into parallel signal groups each containing said skew compensation pattern, a plurality of delay buffers for delaying the individual parallel signal groups outputted from the demultiplexing, and a delay controller for extracting the skew compensation pattern from each of said parallel signal groups outputted from the demultiplexing,
- wherein said delay controller controls a delay time in each of said delay buffers depending on a state of the extracted skew pattern.
A skew compensation method comprising the steps of:
- demultiplexing a parallel signal to be transmitted into a plurality of parallel signal streams;
- inserting a skew compensation pattern in each of the parallel signal streams resulting from the demultiplexing;
- converting each of the plurality of parallel signal streams containing the skew compensation pattern into a serial signal;
- transmitting the plurality of serial signals to a transmission line unit;
- receiving the plurality of serial signals from said transmission line unit;
- demultiplexing each of the received serial signals into parallel signal streams each containing the skew compensation pattern;
- extracting the skew pattern from each of the parallel signal streams;
- delaying at least one of said parallel signal streams by a delay time determined depending on a phase of the extracted skew pattern;
- and
- multiplexing the parallel signal streams partially delayed into an original parallel signal.
A skew compensation method according to claim. 14, further comprising the step of wavelength-multiplexing the plurality of serial signals each containing the skew compensation pattern, wherein the wavelength-multiplexed signals are transmitted to said transmission line unit.
Dependencies are inferred from the claim text.