A memory interface may include a transmitter that generates multi-level signals made up of symbols that convey multiple bits of data. The transmitter may include a first data path for a first bit (e.g., a least significant bit (LSB)) in a symbol and a second data path for a second bit (e.g., the most significant bit (MSB)) in the symbol. Each path may include a de-emphasis or pre-emphasis buffer circuit that inverts and delays signals received at the de-emphasis or pre-emphasis buffer circuit. The delayed and inverted data signals may control de-emphasis or pre-emphasis drivers that are configured to apply de-emphasis or pre-emphasis to a multi-level signal.

A data equalization system includes a data clock input configured to receive a clock signal. There is an input node operative to receive a data signal of transmission symbols that change state synchronously with the clock signal. There is a first tap coupled to the input node. A second tap is configured to receive a variation of the data signal. At least one of a weight of the first tap or a weight of the second tap is modulated by a dynamic control parameter that repeats synchronously with each transmission symbol.

The present invention is directed to communication methods and systems thereof. In a specific embodiment, a noise cancelation system includes a slicer that processes a data stream generates both PAM symbols and error data. An RIN estimator generates RIN data based on the PAM symbols and the error data. A filter removes non-RIN information from the RIN data. The filtered RIN data includes an offset term and a gain term, which are used to remove RIN noise from the data stream. There are other embodiments as well.

The present invention is directed to communication methods and systems thereof. In a specific embodiment, a noise cancelation system includes a slicer that processes a data stream generates both PAM symbols and error data. An RIN estimator generates RIN data based on the PAM symbols and the error data. A filter removes non-RIN information from the RIN data. The filtered RIN data includes an offset term and a gain term, which are used to remove RIN noise from the data stream. There are other embodiments as well.

A signaling circuit having a selectable-tap equalizer. The signaling circuit includes a buffer, a select circuit and an equalizing circuit. The buffer is used to store a plurality of data values that correspond to data signals transmitted on a signaling path during a first time interval. The select circuit is coupled to the buffer to select a subset of data values from the plurality of data values according to a select value. The equalizing circuit is coupled to receive the subset of data values from the select circuit and is adapted to adjust, according to the subset of data values, a signal level that corresponds to a data signal transmitted on the signaling path during a second time interval.

A reception device includes an equalization processing unit including a linear filter unit and a nonlinear filter unit and performing equalization process on a reception signal; a linear propagation channel estimation unit making propagation channel estimation using a known signal included in a reception signal to calculate a filter coefficient of the linear filter unit; and a synchronization processing unit performing synchronization process of correcting frequency deviation based on a signal output by the equalization processing unit, and when a predetermined condition is satisfied after executing first equalization process of outputting a reception signal filtered by the linear filter unit to the synchronization processing unit, the equalization processing unit starts second equalization process that is an adaptive equalization process of outputting a result of addition of a reception signal filtered by the linear filter unit and a reception signal filtered by the nonlinear filter unit to the synchronization processing unit.

A system for controlling equalization applied to a received signal comprising an equalizer configured to equalize on a received signal to generate an equalized signal, and a clock recovery module configured to recover a clock signal from the equalized signal or the received signal. A clock adjustment system is configured to receive the clock signal, and at least one control signal, to create a sampling clock signal. A filter is configured to filter the equalized signal to create a filtered signal. A sampling unit samples the filtered signal or the equalized signal such that the output of the sampling unit is provided to a controller. The controller is configured to receive and process the output of the sampling unit to generate a boost signal, and the controller is further configured to provide the boost signal to the equalizer to control the amount of equalization performed by the equalizer.

A Decision Feedback Equalizer (DFE) for filtering N symbols includes multiple processing blocks and selection logic. Each of the processing blocks includes a respective number N<N of lookahead modules. The processing blocks are arranged in groups of L processing blocks, and each processing block in a group receives (i) N symbols selected for the group from among the N symbols, and (ii) a predefined speculative value of a DFE output, and produces, based on the N symbols and on the predefined speculative value, N respective lookahead values. N1 of the N lookahead values are used in a chained calculation that meets a timing constraint that is not met by the chained calculation performed on N lookahead values. The selection logic selects one of the L lookahead values in each group of the L processing blocks for each of the N symbols, and outputs N lookahead values in parallel.

Technologies for jitter extraction are described. A receiver device includes an analog-to-digital converter (ADC) and a signal processing circuit. The signal processing circuit includes an equalizer block to output current data based on samples from the ADC. A clock-recovery (CR) block includes a timing error detector (TED) or a phase detector to measure a sampling offset. The CR block can use the sampling offset to control sampling of subsequent data by the ADC. A jitter extraction block can use the sampling offset to re-sample the current data to obtain re-sampled data based on the sampling offset to remove jitter from the current data.

Pre-charging two or more sets of nodes to set a differential output of a multi-input summation latch connected to the two or more sets of nodes in a pre-charged state, the two or more sets of nodes comprising a set of data signal nodes and a set of DFE correction nodes, in response to a sampling clock, generating a differential data voltage and an aggregate differential DFE correction signal, and generating a data decision by driving the differential output of the multi-input summation latch into one of two possible output states according to a summation of the differential data voltage signal and the aggregate differential DFE correction signal and subsequently holding the data decision by holding the differential output of the multi-input summation latch in a latched state for a duration determined by the sampling clock.