Abstract: A method for recoding an input sequence of words, including assigning a respective bit-grade to at least one of the bits in a first word in the input sequence, deriving candidate words from the first word in response to the respective bit-grade, and inserting one of the candidate words into each of a plurality of candidate sequences, so that each of the candidate sequences contains one of the candidate words. The method further includes adding subsequent words to the candidate sequences, the subsequent words consisting of a further candidate word derived from a further word in the input sequence, computing respective sequence parameters for the candidate sequences, based on a relation between the candidate words and the subsequent words in the candidate sequences, selecting one of the candidate sequences in response to the sequence parameters, and outputting one of the candidate words contained in the selected candidate sequence.

Abstract: A receiver for deserializing a stream of data bits, including a single clock which is adapted to generate a first plurality of clock phases, and a sample generator which is adapted to sample the stream so as to generate initial data values of each of the bits at times defined by the first plurality of clock phases. The receiver further includes digital circuitry which is adapted to group the initial values into a second plurality of sampling phase sets, according to the clock phases at which the values were sampled, and assign each of the phase sets a respective grade in response to at least some of the initial values. The circuitry selects a decoding phase set from the phase sets in response to the respective grades, and decodes the stream in response to initial values of the decoding phase set to generate decoded values of the consecutive bits.

Abstract: Signal processing apparatus, including a circuit which processes signals received on multiple channels so as to extract therefrom at least first and second sequences of symbols, and a FIFO, which receives and stores at least one bit of each of the symbols in a first interval of the first sequence and a second interval of at least the second sequence, the second interval at least partially overlapping the first interval. The apparatus includes a predictor, which determines, for each of the symbols in the first interval of the first sequence an expected value of the at least one bit in a corresponding one of the second symbols in the second interval, and logic, which compares the expected value with the at least one bit of each of the second symbols in the FIFO, so as to determine a relative skew between the first and at least the second channel.

Abstract: An equalizer, consisting of a plurality of taps, each tap having a multiplier which is coupled to multiply a respective input sample by a respective coefficient, the taps being arranged in sequence so that the input sample to each of the taps, except to a first tap in the sequence, is delayed relative to a preceding tap in the sequence. The equalizer further includes an input selector, which is coupled to toggle the input sample to at least a selected tap among the plurality of taps, responsive to a state of the equalizer, so that the equalizer operates in a first state as a feed forward equalizer, and in a second state as a blind equalizer.

Abstract: A finite impulse response filter, including a plurality of taps arranged to receive and process a sequence of input data samples so as to generate a filter output. Each tap consists of a multiplier operating in one's complement arithmetic, the multiplier being coupled to multiply a respective input sample from the sequence by a respective equalization coefficient, and an adder, which sums an output from the multiplier. The taps are arranged in sequence so that the input sample to each of the taps, except to a first tap in the sequence, is delayed relative to a preceding tap in the sequence. The filter also includes an adjustment-accumulator coupled to receive the filter output and responsive thereto to generate an adjustment that is adapted to correct the filter output to a twos complement result, and an adjustment-adder which sums the adjustment and the filter output to generate a final output.

Abstract: Apparatus for recovering timing of data input to a receiver, the apparatus consisting of an interpolator which receives the input data and generates interpolated-data in response to an interpolation coefficient, and a feed-forward equalizer having at least three taps. Each tap consists of a multiplier which is coupled to multiply a respective input sample by a respective adaptive equalization coefficient. The taps are arranged in sequence so that the input sample to each of the taps, except to a first tap in the sequence, is delayed relative to a preceding tap in the sequence. The equalizer receives and equalizes the interpolated-data so as to generate equalized-data from the interpolated-data. The apparatus also includes a timing sensor which adjusts the interpolation coefficient responsive a third adaptive equalization coefficient comprised in the equalization coefficients.

Abstract: By applying additional error correction during transmission of any 8B/10B pattern without increasing the number of overhead bits, improved performance is possible, while still maintaining the other advantages of the 8B/10B code. In effect, a new “coding layer” is added wherein the 8B/10B encoded data goes through a low latency encoding process during transmission, and is regenerated by a complementary low latency decoding process during the receive process, to provide a coding gain of the code of about 5-6 dB (from about BER=le−5 to about BER=le−17) by detecting and correcting errors during transmission in the communication channel. Moreover, it is now possible to have an additional communication channel between both end stations with a side-band channel data rate of about 16 mbps. The original 8B/10B data stream data rate remains the same and the user gets the benefits of the error correction and additional communication channel without any bandwidth penalty.

Abstract: A receiver of baseband signals from a communications line characterized by baseline wander, including a pre-decoding section, which receives and samples the signals and subtracts each sample from a preceding sample so as to generate corrected data, and an equalization section, which receives the corrected data and generates equalized output data representative of data input to the line and generally free of the baseline wander. The receiver preferably includes an A/D converter, which digitizes the signals either before or after pre-decoding.

Abstract: A method for determining a measure of the length of a link between a transmitter and a receiver within a communication network, including: conveying signals from the transmitter to the receiver in accordance with normal network operation, and then processing the received signals to determine the measure of the length, responsive to a length-dependent effect of the link on the signals. The method may be performed without removing the link from the network.

Abstract: A method for determining whether signal data exists on a communication line, including: receiving a signal from the line; measuring a level of the received signal at a plurality of predetermined times; comparing the measured levels with predetermined reference levels so as to identify a plurality of valid data pulses; measuring a time interval between two or more of the valid data pulses; and determining that the valid pulses represent signal data responsive to the measured time interval.

Abstract: A receiver of baseband signals from a communications line characterized by baseline wander, including a pre-decoding section, which receives and samples the signals and subtracts each sample from a preceding sample so as to generate corrected data, and an equalization section, which receives the corrected data and generates equalized output data representative of data input to the line and generally free of the baseline wander. The receiver preferably includes an A/D converter, which digitizes the signals either before or after pre-decoding.

Abstract: A receiver of baseband signals from a communications line characterized by baseline wander, including a pre-decoding section, which receives and samples the signals and subtracts each sample from a preceding sample so as to generate corrected data, and an equalization section, which receives the corrected data and generates equalized output data representative of data input to the line and generally free of the baseline wander. The receiver preferably includes an A/D converter, which digitizes the signals either before or after pre-decoding.