Ethernet system

In combination for use in a system providing signals having individual ones of a plurality of analog levels to represent information,

• a hub,
• a computer displaced from the hub,
• a plurality of twisted pairs of wires extending between the hub and the computer,
• one of the twisted pairs of wires providing only for the transmission of the signals from the computer to the hub,
• a second one of the twisted pairs of wires providing only for the reception at the computer of the signals from the hub,
• third and fourth ones of the twisted pairs of wires providing for the transmission of the signals from the computer to the hub and the reception at the computer of the signals from the hub,
• first mews responsive at the computer to the signals received at the computer through the second, third and
• fourth ones of the twisted pairs for providing a digital conversion of such signals at a particular frequency,
• timing recovery means responsive to the digitally converted signals from the first means for regulating the frequency of the digital conversion by the first means at the particular frequency, and
• digital adaptive equalizer means responsive to the signals from the first means for selecting individual ones of the analog levels closest in the plurality to the magnitudes of the digitally converted signals.

In combination for use in a system providing signals having individual ones of a plurality of analog levels to represent information,

• a hub,
• a computer displaced from the hub,
• a plurality of twisted pairs of wires between the hub and the computer, individual ones of the twisted pairs of wires either transmitting or receiving the digital signals and other ones of the twisted pairs of wires selectively transmitting and receiving the digital signals,
• first means responsive to the signals received in the twisted pairs of wires for providing a digital conversion of the received signals at a particular rate,
• second means responsive to the digitally converted signals from the first means for regulating the rate of the digital conversion of the received signals at the particular rate, and
• third means responsive to the digitally converted signals from the first means for converting the magnitudes of such digitally converted signals to the individual ones of the analog levels closest to such magnitudes and for recovering the information represented by such analog levels.

In combination for use in a system providing signals having individual ones of a plurality of analog levels representing information,

• a hub,
• a computer displaced from the hub,
• a plurality of twisted pairs of wires between the hub and the computer, individual ones of the twisted pairs of wires either transmitting or receiving the signals and other ones of the twisted pair of wires selectively transmitting and receiving the signals,
• the signals being provided in packets each including a preamble providing a plurality of timing signals and, after the preamble, a plurality of data signals representing the information,
• first means responsive to the signals received in the twisted pairs of wires in the plurality for providing a digital conversion of the received signals at a particular rate,
• second means responsive to the timing signals in the preamble in each packet and providing a first gain for regulating at the particular rate the digital conversion by the first means of the received signals,
• third means responsive to the data signals representing the information in each packet and providing a second gain lower than the first gain for regulating at the particular rate the digital conversion by the first means of the received signals, and
• fourth means responsive to the digital conversions from the first means of the data signals for converting such digital conversions to the information represented by such digital conversions.

In combination for use in a system providing signals having individual ones of a plurality of analog levels representing information and providing a computer and a hub displaced from the computer and a plurality of twisted pairs of wires between the hub and the computer, individual ones of the twisted pairs of wires either transmitting or receiving the signals and other ones of the twisted pair of wires selectively transmitting and receiving the signals,

• the signals being provided in packets each having a preamble providing a plurality of timing signals and, after the preamble, a plurality of data signals representing the information,
• first means disposed in the computer and responsive to the signals received in the twisted pairs of wires for providing a digital conversion of the received signals at a particular rate,
• second means disposed in the computer and responsive to the preamble in each packet for regulating with a first gain factor the digital conversion of the received signals at the particular rate,
• third means disposed in the computer and responsive to the digital conversions of the data signals representing the information in each packet for regulating with a second gain factor lower than the first gain factor the digital conversion of such data signals at the particular rate, and
• fourth means disposed in the computer and responsive to the digital conversions of the data signals from the first means for converting such digital conversions to the information represented by such digital conversions.

In combination for use in a system including a hub and a plurality of twisted pairs of wires to provide packets of signals where each packet includes a preamble defined by a plurality of timing signals and includes a plurality of data signals following the preamble, each of the data signals having an individual one of a plurality of analog values to represent information and where the timing signals and the data signals in the packets are transmitted through the twisted pairs of wires from the hub,

• a computer displaced from the hub for receiving the packets including the timing signals in preamble and the data signals representing the information,
• the computer including a plurality of channels each responsive to the packets received by the computer from an individual one of the pairs of the twisted wires,
• each individual one of the channels including first means for providing digital conversions at the particular rate of the signals received in each packet in such channel,
• each individual one of the channels including second means responsive to the digital conversions from the first means in each of the channels for operating upon such signals to regulate the digital conversions of the received signals by the first means at the particular rate, and
• each individual one of the channels including third means responsive to the digital conversions of the data signals from the first means in such channel for selecting the individual ones of the analog values in the plurality closest in magnitude to the digital conversions of the data signals received in such channel.

In combination for use in a system including a hub and a plurality of twisted pairs of wires to provide packets of signals where each packet includes a preamble defined by a plurality of timing signals and includes a plurality of data signals having individual ones of a plurality of analog levels to represent information and where

• the signals in the packets are transmitted through a plurality of the twisted pairs of wires from the hub,
• a computer displaced from the hub for receiving the packets including the timing signals in the preamble and the data signals transmitted from the hub,
• the computer including a plurality of channels each individual one of which receives the signals in the packets in at least an individual one of the twisted pairs,
• each individual one of the channels including first means for providing an automatic gain control of the signals in the packets in such channel,
• each individual one of the channels including second means for providing a digital conversion at a particular rate of the signals in the packets from the first means in such channel,
• each individual one of the channels including third means responsive to the signals from the second means in such channel for regulating the gain of the signals from the first means in such channel at a particular value,
• each individual one of the channels including fourth means responsive to the digital conversions from the second means in such channel for selecting the individual ones of the analog levels in the plurality closest in magnitude to the digital conversions of the data signals in each packet from the second means,
• each individual one of the channels including fifth means responsive to the digital conversions from the second means for regulating at the particular rate the digital conversion of the signals in the packets in such channel by the second means.

In combination for use in a system providing signals having individual ones of a plurality of analog levels to represent information,

• a hub,
• a computer,
• a plurality of pairs of twisted wires connecting the hub and the computer,
• a first one of the twisted pairs of wires being only for transmission of the signals from the computer to the hub, a second one of the twisted pairs of wires being only for the reception of the digital signals at the computer from the hub and third and fourth ones of the twisted pairs of wires being for the selective transmission of the signals from the computer to the hub and for the selective reception of the signals at the computer from the hub,
• first means at the computer for transmitting the signals through the individual ones of the first, third and fourth pairs of the twisted wires from the computer to the hub,
• second means at the computer for receiving the signals passing through the individual ones of the second, third and fourth pairs of the twisted wires from the hub,
• a media access controller for establishing a priority between the signals received by the computer and the signals transmitted by the computer when the received and transmitted signals occur simultaneously,
• a plurality of third means each responsive in the computer to the digital signals received through an individual one of the second, third and fourth twisted pairs of wires for providing a digital conversion of such signals at a particular rate,
• a plurality of fourth means each responsive in the computer to the digital conversions of the signals from an individual one of the third means in the plurality for regulating the digital conversions by such individual one of the third means at the particular rate, and
• a plurality of fifth means each responsive in the computer to the digital conversions from an individual one of the third means in the plurality for establishing for each of such digital conversions an individual one of the plurality of analog levels closest in magnitude to such digital conversions from the first means.

In combination for use in a computer included in a system having a hub for providing packets of signals where each packet includes a preamble defined by a plurality of timing signals and includes a plurality of data signals having individual ones of a plurality of analog levels to represent information,

• first means for receiving the packets of the signals from the hub,
• second means responsive to the signals in the packets received from the hub for providing a digital conversion of such signals at a particular rate,
• third means responsive to the digital conversions from the second means and the timing signals in the preamble in each packet for producing a first output dependent upon the occurrence of such timing signals relative to the digital conversions from the second means,
• fourth means responsive to the digital conversions from the second means and the data signals following the preamble in each packet for producing a second output dependent upon the occurrence of the data signals in the packets relative to such digital conversions,
• fifth means for providing clock signals at a rate constituting an integral multiple of the particular rate, and
• sixth means selectively responsive to the first output from the third means and the second output from the fourth means for passing individual ones of the clock signals from the fifth means to the second means in accordance with the selected ones of the first and second outputs to obtain a regulation of the digital conversions by the second means oat the particular rate.

In combination for use in a system having a hub for providing packets of signals where each packet includes a preamble defined by a plurality of tinting signals and includes a plurality of data signals having individual ones of a plurality of analog levels to represent information,

• first means for receiving the signals in each packet,
• second means responsive to the signals received in each packet for providing digital conversions of such signals at a particular rate,
• third means responsive to the digital conversions from the second means for producing individual ones of the analog levels in the plurality, the individual one of the analog levels for each of the digital conversions being that analog level closest to the peak amplitude of such digital conversion,
• fourth means responsive to the digital conversions from the second means in each packet for regulating the digital conversions of the received signals in each packet at the particular rate, and
• fifth means responsive to the individual ones of the analog levels from the third means for converting such analog levels to the information represented by the data signals in the packets.

In combination for use in a system having a hub for providing packets of signals where each packet includes a preamble defined by a plurality of timing signals and includes a plurality of data signals following the preamble and having individual ones of a plurality of analog levels to represent information,

• first means for receiving the signals in each packet,
• second means for providing digital conversions of the received signals in each packet at a particular rate,
• third means responsive to the digital conversions from the second means during the occurrence of the timing signals in the preamble in each packet for determining the amplitudes and polarities of such digital conversions at the times assumed by the third means to constitute the peaks and zero crossings of such digital conversions,
• fourth means responsive to first patterns in the amplitudes determined by the third means at the times assumed by the third means to constitute the peaks and zero crossings of such digital conversions for providing a first phase adjustment in the digital conversions from the second means,
• fifth means responsive to second patterns in the amplitudes determined by the third means at the times assumed by the third means to constitute the peaks and zero crossings of such digital conversions for providing a second phase adjustment in the digital conversions from the second means, and
• sixth means responsive to the digital conversions from the second means for recovering the information represented by the signals in the packets,
• the first phase adjustment being different from the second phase adjustment.

In combination for use in a system having a hub for providing packets of signals where each packet includes a preamble defined by a plurality of timing signals and includes a plurality of data signals following the preamble and having individual ones of a plurality of analog levels to represent information,

• first means for receiving the signals in each packet,
• second means for providing a digital conversion of the received signals in each packet at a particular rate,
• third means for providing digital outputs at progressive times during each digital conversion from the second means,
• fourth means for operating upon the digital conversions from the second means during the occurrence of the timing signals in the preamble in each packet at times assumed by the fourth means to constitute the peaks and zero crossings of such digital conversions to determine the amplitudes and polarities of the digital conversions at such times,
• fifth means responsive in each cycle of the timing signals in the preamble in each packet to the amplitudes and polarities determined for the digital conversions in such cycle to select a particular one of the digital outputs at the progressive times from the third means for providing the digital conversions by the second means,
• sixth means responsive to the digital conversions by the second means of the data signals following the preamble in each packet for selecting the analog levels of such data signals closest in magnitudes to the peaks of the digital conversions, and
• seventh means responsive to the analog levels selected by the sixth means for recovering the information represented by such analog levels.

In combination for use in a system having a hub for providing packets of signals where each packet includes a preamble defined by a plurality of timing signals and includes a plurality of data signals following the preamble and having individual ones of a plurality of analog levels to represent information,

• first means for receiving the signals in each packet,
• second means for providing a digital conversion of the received signals in each packet at a particular rate,
• third means for operating upon the digital conversions from the second means during the occurrence of the timing signals in the preamble in each packet at times assumed by the third means to constitute the peaks and zero crossings of such digital conversions to determine the amplitudes and polarities of such digital conversions at such assumed times,
• fourth means responsive in each cycle of the timing signals in the preamble in each packet to a first relationship in the amplitudes and polarities of the digital conversions at such assumed times in such cycle for providing a first adjustment in subsequent cycles of the timing signals in the times assumed by the third means to constitute the peaks and zero crossings of the digital conversions in the preamble in such packet,
• fifth means responsive to the operation of the fourth means in providing the first adjustment in the times assumed by the third means to constitute the peaks and zero crossings of the digital conversions in the preamble of such packet for preventing any further ones of such first adjustments in such assumed times in the preamble in such packet,
• sixth means responsive in each cycle of the timing signals in the preamble in each packet to a second relationship in the amplitudes and polarities of the digital conversions at such assumed times in such cycle for providing a second adjustment, less than the first adjustment, in subsequent cycles of the timing signals in the times assumed by the third means to constitute the peaks and zero crossings in the preamble in such packet, and
• seventh means responsive to the adjustments in the times assumed by the third means to constitute the peaks and zero crossings of the digital conversions in the preamble in each packet for providing corresponding adjustments in the time for the digital conversion of the data signals in such packet to regulate the digital conversions of the data signals at the particular rate.

In combination for use in a system having a hub for providing packets of signals where each packet includes a preamble defined by a plurality of timing signals and includes a plurality of data signals following the preamble and having individual ones of a plurality of analog levels to represent information,

• first means for receiving the signals in each packet,
• second means for providing a digital conversion at a particular rate of the received signals in each packet,
• third means for determining, for each of the digital conversions following the preamble in each packet, the individual one of the analog levels closest in magnitude to the peak of such digital conversions,
• fourth means for operating upon the digital conversions from the second means, during the occurrence of the data signals following the preamble in each packet, at times assumed by the fourth means to constitute the peaks and zero crossings in such digital conversions to respectively determine the amplitude levels from the second means at such assumed times,
• fifth means responsive to the amplitude levels determined by the fourth means for each digital conversion of the data signals for providing adjustments in the rate of the digital conversions by the second means to regulate such digital conversions at the particular rate, and
• sixth means for preventing the operation of the fourth means during the occurrence of the timing signals in each packet and during the time between the occurrence of successive packets.

In combination for use in a system having a hub for providing packets of signals where each packet includes a preamble defined by a plurality of timing signals and includes a plurality of data signals having individual ones of a plurality of analog levels to represent information,

• first means for receiving the signals in each packet
• second means responsive to the signals received in each packet for providing a digital conversion of such signals at a particular rate,
• third means for determining the phase and amplitude of the digital conversions from the second means at the times assumed by the third means to be the peaks and zero crossings of such digital conversions,
• fourth means responsive to the phases and amplitudes determined by the third means during the timing signals in the preamble in each packet for providing first adjustments in the rate of such digital conversions to regulate the digital conversions at the particular rate,
• fifth means responsive to each digital conversion following the preamble in each packet for selecting the analog level closest in the plurality to the peak assumed by the third means in such digital conversion, and
• sixth means responsive to the phases and amplitudes determined by the third means in the digital conversion during the data signals in each packet for providing second adjustments in the rate of such digital conversions to regulate at the particular rate the digital conversions of the data signals.

In combination for use in a system having a hub for providing packets of signals where each packet includes a preamble defined by a plurality of timing signals and includes a plurality of data signals having individual ones of a plurality of analog levels to represent information,

• first means for receiving the signals in each packet,
• second means responsive to the signals received in each packet for providing a digital conversion of such signals at a particular rate,
• third means for determining the phases and amplitudes of the digital conversions from the second means at times assumed by the third means to be the peaks and zero crossings of such digital conversions,
• fourth means responsive to the amplitudes and phases of the peaks and zero crossings determined by the third means in the preamble in each packet for adjusting the rate of such digital conversions in accordance with such amplitudes and phases to regulate the digital conversions at the particular rate,
• fifth means for boosting the gain of the digital conversions from the second means when the amplitudes of the peaks and zero crossings from the second means are below a particular value, and
• sixth means responsive to the digital conversions from the second means for recovering the information represented by the digital conversions following the preamble in each packet.

In combination for use in a system having a hub for providing packets of signals where each packet includes a preamble defined by a plurality of timing signals and includes a plurality of data signals having individual ones of a plurality of analog levels to represent information,

• first means for receiving the signals in each packet
• second means responsive to the signals received in each packet for providing a digital conversion of such signals at a particular rate,
• third means for determining the magnitudes of the digital conversions from the second means at the times assumed by the third means to be the peaks and zero crossings of such digital conversions,
• fourth means responsive to die magnitudes of the peaks and zero crossings determined by the third means in each preamble in each packet for providing first adjustments in the rate of such digital conversions when the magnitudes of such determinations have a first particular relationship, thereby to regulate the digital conversions at the particular rate,
• fifth means for providing a phase inversion in the times of the determinations of the peaks and zero crossings by the third means of the digital conversions in the timing signals when the magnitudes of such determinations have a second particular relationship different from the first particular relationships thereby to adjust the rate of the digital conversions in a direction to regulate the digital conversions at the particular rate,
• the phase inversions being greater in phase than the first adjustments, and
• sixth means for preventing any other adjustments in the rate of the digital conversions at the time that the phase inversion is being provided by the fifth means.

A bidirectional data communication system comprising:

• communication signals having individual ones of a plurality of analog levels to represent information;
• a plurality of signal lines disposed in pairs and defining a multi-pair communication environment, each signal line transmitting or receiving said communication signals;
• a transmitter block, including a plurality of transmitters, each coupled to particular ones of the signal line pairs;
• a receiver block, including a plurality of receivers, each coupled to particular ones of the signal line pairs, each receiver including;
• an analog to digital converter configured to convert a plurality of analog levels into a corresponding plurality of digital levels defining a digital signal;
• and
• a fully digital adaptive equalizer coupled to the analog to digital converter and operating on the digital signal to define information represented by the plurality of digital levels;
• the receiver block further comprising timing recovery circuitry coupled to receive the digital signal from the analog to digital converter and extract timing information therefrom, the analog to digital converter operatively responsive to said timing information and performing digital conversions at a rate defined thereby;
• wherein the communication signals are provided in packets, each packet comprising a preamble portion and a data containing portion, the preamble portion including timing signals;
• and
• wherein the timing recovery circuitry comprises a first timing loop having a high gain stage and a second timing loop having a low gain stage, the first timing loop locking the analog to digital converter in phase with the preamble portion the second timing loop locking the analog to digital converter in phase with the data containing portion.

A bidirectional data communication system comprising:

• communication signals having individual ones of a plurality of analog levels to represent information;
• a plurality of signal lines disposed in pairs and defining a multi-pair communication environment, each signal line transmitting or receiving said communication signals;
• a transmitter block, including a plurality of transmitters, each coupled to particular ones of the signal line pairs;
• a receiver block, including a plurality of receivers, each coupled to particular ones of the signal line pairs, each receiver including;
• an analog to digital converter configured to convert a plurality of analog levels into a corresponding plurality of digital levels defining a digital signal;
• and
• a fully digital adaptive equalizer coupled to the analog to digital converter and operating on the digital signal to define information represented by the plurality of digital levels;
• the receiver block further comprising timing recovery circuitry coupled to receive the digital signal from the analog to digital converter and extract timing information therefrom, the analog to digital converter operatively responsive to said timing information and performing digital conversions at a rate defined thereby;
• digital adaptive equalizer further comprising:
• a feed forward equalizer having an input receiving the digital signal from the analog to digital converter and an output;
• slicer coupled to receive the digital signal from the feed forward equalizer and outputting a signal representing a symbol, the signal characterized by the digital levels;
• an adder disposed between the feed forward equalizer and the slicer;
• and
• a decision feedback equalizer having an input receiving the signal output by the slicer and an output coupled to the adder, the adder summing the output of the decision feedback equalizer with the output of the feed forward equalizer.

A bidirectional data communication system comprising:

• communication signals having individual ones of a plurality of analog levels to represent information;
• a plurality of signal lines disposed in pairs and defining a multi-pair communication environment, each signal line transmitting or receiving said communication signals;
• a transmitter block, including a plurality of transmitters, each coupled to particular ones of the signal-line pairs;
• a receiver block, including a plurality of receivers, each coupled to particular ones of the signal line pairs, each receiver including;
• an analog to digital converter configured to convert a plurality of analog levels into a corresponding plurality of digital levels defining a digital signal;
• an automatic gain control circuit coupled in feedback fashion to the analog to digital converter and operatively responsive to output signals therefrom to control the gain of received communication signals;
• and
• a fully digital adaptive equalizer coupled to the analog to digital converter and operating on the digital signal to define information represented by the plurality of digital levels;
• the digital adaptive equalizer further comprising:
• a feed forward equalizer having an input receiving the digital signal from the analog to digital converter and an output;
• a slicer coupled to receive the digital signal from the feed forward equalizer and outputting a signal representing a symbol, the signal characterized by the digital levels;
• an adder disposed between the feed forward equalizer and the slicer;
• and
• a decision feedback equalizer having an input receiving the signal output by the slicer and an output coupled to the adder, the adder summing the output of the decision feedback equalizer with the output of the feed forward equalizer.

In a bidirectional communication system, a method of processing signals received through a multi-pair transmission medium, the signals having characteristic values occurring at a characteristic frequency, the method comprising:

• providing an A/D converter cooled to receive the signals from the transmission medium;
• providing a sampling clock signal at a sampling clock frequency equal to the characteristic occurrence frequency of received signal characteristic values;
• sampling the received signals in the A/D converter at the sampling clock frequency;
• generating signal samples at the sampling clock frequency, each signal sample being output from the A/D at a time assumed to correspond to the occurrence of a signal characteristic value;
• processing each signal sample in a timing recovery circuit coupled, in feedback fashion, between the output of the A/D and a sampling clock input thereto;
• determining whether the occurrence of a signal characteristic value leads or lags the sampling clock signal in phase;
• and
• adjusting the phase of the sampling clock signal such that each signal sample is output from the A/D at a time that actually corresponds to the occurrence of a signal characteristic value, a sampling clock phase thereby being locked to a corresponding phase of a signal characteristic value;
• wherein the received signals are analog signals disposed in packets, each packet of the analog signals disposed in packets being divided into a first packet region comprising timing signals and a second packet region comprising data signals, the method further comprising:
• sampling the received data signals in the A/D converter at the sampling clock frequency, wherein the data signals are sampled after the phase of the sampling clock signal has been locked to the phase of a signal characteristic value of the timing signals.

In a bidirectional communication system, a method of processing analog signal packets received through a multi-pair transmission medium, each analog signal packet including a plurality of signals having characteristic values occurring at a characteristic frequency, the method comprising:

• providing a sampling clock signal at a sampling clock frequency equal to the characteristic occurrence frequency of received signal characteristic values;
• predicting an occurrence time corresponding to the characteristic occurrence frequency of received signal characteristic values;
• sampling the received signals at the sampling clock frequency and at the predicted occurrence time to thereby generate signal samples at the sampling clock frequency, each signal sample assumed to correspond to the occurrence of a signal characteristic value;
• processing the signal samples in a high gain error generator the high gain error generator determining whether the occurrence of a signal characteristic value leads or lags the sampling clock signal in phase;
• and
• adjusting the phase of the sampling clock signal such that each signal sample is generated at a time that actually corresponds to the occurrence of a signal characteristic value, the sampling clock having an occurrence time locked in phase with a corresponding occurrence of a signal characteristic value;
• the signals of each analog signal packet being characterized by a plurality of analog amplitude values, the values of the analog amplitudes defining information content, the method further comprising:
• dividing each analog signal packet into a first packet region comprising timing signals and a second packet region comprising data signals;
• and
• converting the analog amplitude values of the data signals to digital representations thereof by an A/D converter after the occurrence time of the sampling clock signal has been locked to the occurrence time of a signal characteristic value of the timing signals.