Digital receiver systems and clock recovery techniques for use in digital receiver systems are provided to implement asynchronous baud-rate clock recovery systems for high data rate serial receivers multilevel line modulation. A two-stage postcursor ISI equalization system is provided to efficiently emulate a 4-level DFE (decision feedback equalization) system, for example, while converting a 4-level equalized signal to s 2-level equalized signal. For example, a two stage postcursor ISI equalization system includes a DFE stage which operates on a most significant component of a given 4-level data symbol, followed by a DFFE (decision-feedforward equalizer) stage which operates on a least significant component of the given 4-level data symbol. In parallel with the DFFE stage, an estimate of the least significant component is subtracted from the equalized 4-level data symbol to convert the 4-level data symbol to a 2-level symbol.

Digital receiver systems and clock recovery techniques for use in digital receiver systems are provided to implement asynchronous baud-rate clock recovery systems for high data rate serial receivers multilevel line modulation. A two-stage postcursor ISI equalization system is provided to efficiently emulate a 4-level DFE (decision feedback equalization) system, for example, while converting a 4-level equalized signal to s 2-level equalized signal. For example, a two stage postcursor ISI equalization system includes a DFE stage which operates on a most significant component of a given 4-level data symbol, followed by a DFFE (decision-feedforward equalizer) stage which operates on a least significant component of the given 4-level data symbol. In parallel with the DFFE stage, an estimate of the least significant component is subtracted from the equalized 4-level data symbol to convert the 4-level data symbol to a 2-level symbol.

Embodiments of the present disclosure relate to methods and device for receiving PAM data stream. In an embodiment, a method comprises receiving a signal stream modulated with pulse amplitude modulation (PAM) associated with a plurality of bit patterns; determining boundary voltages for the plurality of bit patterns; and calibrating, based on the boundary voltages, a threshold voltage for use in recognition of the plurality of bit patterns. In this way, bit patterns may be accurately recognized based on the calibrated threshold voltage.

A digital television (DTV) transmitting system is provided that includes an encoder, a group formatter, a packet formatter and a transmission unit. The group formatter forms data groups where the plurality of second known data sequences are spaced 16 segments apart within at least one of the data groups that includes a transmission parameter inserted between the first known data sequence and the plurality of second known data sequences and the first known data sequence has a first M-symbol sequence and a second M-symbol sequence, the first M-symbol sequence and the second M-symbol sequence have a first pattern, each of the plurality of second known data sequences has a second pattern other than the first pattern, and the second pattern is positioned from a last symbol to a previous N symbol in each of the plurality of second known data sequences.

A programmable logic device (PLD) is augmented with programmable clock data recover (CDR) circuitry to allow the PLD to communicate via any of a large number of CDR signaling protocols. The CDR circuitry may be integrated with the PLD, or it may be wholly or partly on a separate integrated circuit. The circuitry may be capable of CDR input, CDR output, or both. The CDR capability may be provided in combination with other non-CDR signaling capability such as non-CDR low voltage differential signaling (LVDS). The circuitry may be part of a larger system.

The present invention relates generally to integrated circuits. More particularly, the present invention provides a circuit and method for regulating a voltage for a high speed serializer/deserializer (SerDes) device. But it will be recognized that the technique can be used for regulating memory devices (e.g., DDR 4 SDRAM devices, DDR4 register devices, DDR4 controller devices), and other high speed data applications. In various embodiments, phase-interpolator is implemented in conjunction with a delay-lock loop (DLL) and an SR latch, where one or more outputs of the DLL is used by the SR latch. Additionally, such techniques can be used for a variety of applications such as network and/or computer storage systems, computer servers, hand held computing devices, portable computing devices, computer systems, network appliances and/or switches, routers, and gateways, and the like.

Methods and systems for performing data correction and phase optimization are disclosed herein. In some implementations, a system for performing data correction comprises: an analog to digital converter (ADC) configured to receive differential data from a continuous time linear equalizer (CTLE) and generate a bitstream comprising a plurality of data bits and a corresponding plurality of data sign bits; a decision feedback equalization (DFE) block configured to receive the bitstream from the ADC and provide data to a clock and data recovery (CDR) block; and data correction circuitry. In some implementations, the data correction circuitry is configured to: receive the bitstream from the ADC; determine whether to correct a data sign bit; responsive to determining the data sign bit is to be corrected, flip the data sign bit; and provide the plurality of data sign bits, including the flipped data sign bits, to the DFE.

Digital receiver systems and clock recovery techniques for use in digital receiver systems are provided to implement asynchronous baud-rate clock recovery systems for high data rate serial receivers multilevel line modulation. A two-stage postcursor ISI equalization system is provided to efficiently emulate a 4-level DFE (decision feedback equalization) system, for example, while converting a 4-level equalized signal to s 2-level equalized signal. For example, a two stage postcursor ISI equalization system includes a DFE stage which operates on a most significant component of a given 4-level data symbol, followed by a DFFE (decision-feedforward equalizer) stage which operates on a least significant component of the given 4-level data symbol. In parallel with the DFFE stage, an estimate of the least significant component is subtracted from the equalized 4-level data symbol to convert the 4-level data symbol to a 2-level symbol.

A channel equalization and tracking apparatus and method and a receiver. The apparatus includes: a Fourier transforming unit configured to transform a received time-domain signal into a frequency-domain signal; a compensating and equalizing unit configured to perform phase compensation and frequency-domain equalization on the signal outputted by the Fourier transforming unit by using one time of multiplication according to time delay information and an equalizer coefficient; a deciding unit configured to decide the equalized signal; and a channel tracking unit configured to track a channel according to the signal outputted by the Fourier transforming unit and an error signal obtained by the deciding unit. With embodiments of the present disclosure, not only complexity and hardware demands of the whole system are lowered, but also performance of the system is not affected.

An integrated receiver supports adaptive receive equalization. An incoming bit stream is sampled using edge and data clock signals derived from a reference clock signal. A phase detector determines whether the edge and data clock signals are in phase with the incoming data, while some clock recovery circuitry adjusts the edge and data clock signals as required to match their phases to the incoming data. The receiver employs the edge and data samples used to recover the edge and data clock signals to note the locations of zero crossings for one or more selected data patterns. The pattern or patterns may be selected from among those apt to produce the greatest timing error. Equalization settings may then be adjusted to align the zero crossings of the selected data patterns with the recovered edge clock signal.