Taiwan Semiconductor Manufacturing Comp. Ltd.

Diablo Technologies Inc.

Synopsys, Inc.

Dirk Pfaff

Cheng-Hsiang Hsieh

Wei-Li Chen

Chaitanya Palusa

Rob Abbott

Po-Hsiang Lan

Fan-ming Kuo

Rolando Ramirez

Claus Reitlingshoefer

Xin Jie Wang

Riccardo Badalone

David Andrew Yokoyama-Martin

Ralph Mason

Muhammad Nummer

Volodymyr Yavorskyy

Robert Abbott

Stephen Robert Hobbs

Christopher Falkingham

Jingjing Xia

Gholamreza Yousefi Moghaddam

Sivakumar Kanesapillai

A multi-tap Differential Feedforward Equalizer (DFFE) configuration with both precursor and postcursor taps is provided. The DFFE has reduced noise and/or crosstalk characteristics when compared to a Feedforward Equalizer (FFE) since DFFE uses decision outputs of slicers as inputs to a finite impulse response (FIR) unlike FFE which uses actual analog signal inputs. The digital outputs of the tentative decision slicers are multiplied with tap coefficients to reduce noise. Further, since digital outputs are used as the multiplier inputs, the multipliers effectively work as adders which are less complex to implement. The decisions at the outputs of the tentative decision slicers are tentative and are used in a FIR filter to equalize the signal; the equalized signal may be provided as input to the next stage slicers. The bit-error-rate (BER) of the final stage decisions are lower or better than the BER of the previous stage tentative decisions.

Multi-tap decision feed-forward equalizer with precursor and postcursor taps

A communication system includes a receiver device having a continuous time linear equalizer circuitry. The continuous time linear equalizer circuitry includes first gain circuitry, second gain circuitry, second gain circuitry a first capacitor, a first resistive element, a first inductor, and a second resistive element. The first gain circuitry and the second gain circuitry receive an input signal. The first capacitor is connected between an output of the first gain circuitry and an output of the second gain circuitry. The first resistive element is connected between the output of the first gain circuitry and the output of the second gain circuitry. The first inductor is connected to the output of the first gain circuitry, the first capacitor, and the first resistive element. The second resistive element is connected in parallel with the first inductor.

Continuous time linear equalizer with programmable inductive high frequency boost

The present disclosure describes circuits (e.g., clock synthesizers) and methods for producing alternating signals. A clock synthesizer includes an oscillator, a voltage control circuit, and a frequency control circuit. The oscillator produces an output signal with a frequency. The voltage control circuit produces a control voltage for the oscillator based on the frequency of the output signal. The frequency control circuit produces a control signal for the oscillator based on (i) an input voltage to the frequency control circuit and (ii) the control voltage. The control signal causes the oscillator to adjust the frequency of the output signal such that the voltage control circuit adjusts the control voltage to be closer to the input voltage.

Clock synthesizer with dual control

An optimized pulse shaping clock data recovery system is provided that includes a slicer configured to receive a signal and provide an initial set of tentative decisions to a decision feedforward equalizer, where the decision feedforward equalizer provides a fully equalized output signal. The slicer may be incorporated as part of decision feedback equalizer to provide better quality tentative decisions. The clock data recovery system also receives the first output signal that is partially equalized in such a way as to optimally shape it for a clock to sample it at an ideal location by providing an adjustment signal to the analog to digital controller.

SerDes receiver with optimized CDR pulse shaping

Serdes receiver with optimized CDR pulse shaping

The present disclosure describes exemplary line drivers for use in an exemplary wireline transmission device. In some situations, the exemplary line drivers are electrically connected to a wireline communication channel to transmit information. The exemplary line drivers prevent charge sharing with the wireline communication channel. The exemplary line drivers disclosed herein charge various circuit nodes to various logical values, such as a logical zero or a logical one, to prevent charge sharing with the wireline communication channel.

Line drivers for wireline transmission devices

A circuit includes a delay line and a delay locked loop. The circuit is configured to receive a delay parameter and a clock signal. The delay locked loop is configured to generate a pair of control codes based on a frequency of the clock signal and a frequency of an oscillator of the delay locked loop. The delay locked loop is configured to determine a difference between the frequency of the clock signal and the frequency of the oscillator based on a phase of an output of the oscillator and a phase of the clock signal after the output of the oscillator and the clock signal are aligned. The delay line is configured to receive an input signal and generate an output signal delayed from the input signal by a time delay that corresponds to a delay line control code calculated from the pair of control codes and the delay parameter.

Delay locked loop

A novel interpolating phase detector for use in a multiphase PLL is described comprising an array of individual phase comparators, all operating at essentially the same operating point which permits the circuits to be designed simultaneously for high speed and for low power consumption. Two adjacent phase outputs of a multi-phase VCO may be selected and interpolated in between, by selectively attaching a variable number of phase comparators to each phase output and summing their phase error outputs. By varying the number of phase comparators attached to each phase output, interpolation can be achieved with high linearity.

Linear phase interpolator and phase detector

A multi reference phase locked loop (MPLL) generates a high speed clock frequency and phase locks it to a lowest common reference frequency derived from a selected one of at least two reference clocks. One of the reference clocks is a system reference clock in a FBDIMM system, another may be a forwarded clock in an AMB. A prescaler reduces the frequency of at least the forwarded clock to the lowest common reference frequency which is the frequency of the system reference clock. A PLL at the core of the MPLL may be locked to the forwarded clock or the system reference clock for generating a high speed clock. A feedback divider generates the feedback clock for the PLL as well as other clocks required in the system. Furthermore, the MPLL provides a number of clocking modes, including modes to facilitate testing and powering down of sections of the circuitry for conserving power.

Multiple reference phase locked loop

Where high speed communication between a host and memory devices is carried over serial bit lanes, memory buffers are required for converting buffering the serial bit lanes, and for converting between serial and parallel formats. In addition, jitter, wander, and skew between the bit lanes need to be accommodated. The invention discloses a programmable asynchronous FIFO with the integrated ability to convert blocks of bits from serial to parallel as well as inserting bits from a parallel bus into the serial bit stream. The invention provides very low latency and can be implemented in low power technologies.

Growing community of inventors

Ottawa, Canada

Dirk Pfaff