公开(公告)号：US10404236B2

公开(公告)日：2019-09-03

申请号：US16195069

申请日：2018-11-19

Applicant: Rambus Inc.

Inventor： Jared L. Zerbe ,  Brian S. Leibowitz ,  Qi Lin

IPC: H03K3/013 ,  H04L25/06 ,  H04L25/49 ,  H03K5/153 ,  G11C7/02 ,  H04L25/03

Abstract: A system for communicating information between circuits is described. A transmit circuit provides pulse-amplitude-modulation (PAM) signals via a communication channel to a receiver. A circuit in the receiver determines digital values from the received signals using a time-varying threshold voltage, which varies during the bit-time. This approach may compensate for inter-symbol interference (ISI) to increase the voltage and timing margins of the system.

公开(公告)号：US10382023B1

公开(公告)日：2019-08-13

申请号：US15969602

申请日：2018-05-02

Applicant: Rambus Inc.

Inventor： Yue Lu ,  Jared L. Zerbe

IPC: H03K5/00 ,  H03L7/099 ,  H04L7/033 ,  H03L7/24 ,  H03L7/16 ,  H03L7/085 ,  H03L7/083 ,  H03L7/08

Abstract: A clock generating circuit is operated in a phase-locking mode to generate an output clock signal having a first frequency that is phased-locked with respect to a variable-frequency input clock signal. After a frequency transition in the input clock signal, phase-locking is disabled within the clock generating circuit to transition the output clock signal from the first frequency to a second frequency that lacks phase-alignment with the input clock signal, then a frequency-lock range of the clock generating circuit is adjusted to transition the output clock signal from the second frequency to a third frequency that also lacks phase alignment with the input clock signal. After adjusting the frequency-lock range of the clock generating circuit, phase-locking is re-enabled therein to transition the output clock signal from the third frequency to a fourth frequency that is phase-aligned with the variable-frequency input clock signal.

公开(公告)号：US20190196992A1

公开(公告)日：2019-06-27

申请号：US16228695

申请日：2018-12-20

Applicant: Rambus Inc.

Inventor： Jared L. Zerbe ,  Ian P. Shaeffer ,  John Eble

IPC: G06F13/16 ,  G06F1/06 ,  G06F1/04 ,  G06F1/08 ,  G06F1/10 ,  G11C7/22

CPC classification number: G06F13/1689 ,  G06F1/04 ,  G06F1/06 ,  G06F1/08 ,  G06F1/10 ,  G06F13/161 ,  G06F13/1657 ,  G11C7/04 ,  G11C7/222 ,  H04L7/033

Abstract: A memory controller includes a clock generator to generate a first clock signal and a timing circuit to generate a second clock signal from the first clock signal. The second clock signal times communications with any of a plurality of memory devices in respective ranks, including a first memory device in a first rank and a second memory device in a second rank. The timing circuit is configured to adjust a phase of the first clock signal, when the memory controller is communicating with the second memory device, based on calibration data associated with the second memory device and timing adjustment data associated with feedback from at least the first memory device.

公开(公告)号：US20190173697A1

公开(公告)日：2019-06-06

申请号：US16182724

申请日：2018-11-07

Applicant: Rambus Inc.

Inventor： Jared L. Zerbe ,  Fariborz Assaderaghi ,  Brian S. Leibowitz ,  Hae-Chang Lee ,  Jihong Ren ,  Qi Lin

IPC: H04L25/03

CPC classification number: H04L25/03343 ,  H04L25/03057 ,  H04L25/0307 ,  H04L25/03885 ,  H04L2025/03356 ,  H04L2025/03433 ,  H04L2025/03617

Abstract: A transceiver architecture supports high-speed communication over a signal lane that extends between a high-performance integrated circuit (IC) and one or more relatively low-performance ICs employing less sophisticated transmitters and receivers. The architecture compensates for performance asymmetry between ICs communicating over a bidirectional lane by instantiating relatively complex transmit and receive equalization circuitry on the higher-performance side of the lane. Both the transmit and receive equalization filter coefficients in the higher-performance IC may be adaptively updated based upon the signal response at the receiver of the higher-performance IC.

公开(公告)号：US20190149136A1

公开(公告)日：2019-05-16

申请号：US16195069

申请日：2018-11-19

Applicant: Rambus Inc.

Inventor： Jared L. Zerbe ,  Brian S. Leibowitz ,  Qi Lin

IPC: H03K3/013 ,  H04L25/06 ,  H04L25/49 ,  G11C7/02 ,  H03K5/153

CPC classification number: H03K3/013 ,  G11C7/02 ,  H03K5/153 ,  H04L25/03057 ,  H04L25/066 ,  H04L25/4902 ,  H04L25/4917

Abstract: A system for communicating information between circuits is described. A transmit circuit provides pulse-amplitude-modulation (PAM) signals via a communication channel to a receiver. A circuit in the receiver determines digital values from the received signals using a time-varying threshold voltage, which varies during the bit-time. This approach may compensate for inter-symbol interference (ISI) to increase the voltage and timing margins of the system.

公开(公告)号：US10211841B2

公开(公告)日：2019-02-19

申请号：US15667184

申请日：2017-08-02

Applicant: Rambus Inc.

Inventor： Jared L. Zerbe ,  Brian S. Leibowitz ,  Hsuan-Jung Su ,  John Cronan Eble, III ,  Barry William Daly ,  Lei Luo ,  Teva J. Stone ,  John Wilson ,  Jihong Ren ,  Wayne D. Dettloff

IPC: H03L7/00 ,  H03K5/156 ,  G11C7/10 ,  H03L7/091 ,  G11C7/22 ,  H04L7/00 ,  H04L7/033 ,  H03L7/08 ,  H03L7/099 ,  G11C7/04

Abstract: A low-power, high-performance source-synchronous chip interface which provides rapid turn-on and facilitates high signaling rates between a transmitter and a receiver located on different chips is described in various embodiments. Some embodiments of the chip interface include, among others: a segmented “fast turn-on” bias circuit to reduce power supply ringing during the rapid power-on process; current mode logic clock buffers in a clock path of the chip interface to further reduce the effect of power supply ringing; a multiplying injection-locked oscillator (MILO) clock generator to generate higher frequency clock signals from a reference clock; a digitally controlled delay line which can be inserted in the clock path to mitigate deterministic jitter caused by the MILO clock generator; and circuits for periodically re-evaluating whether it is safe to retime transmit data signals in the reference clock domain directly with the faster clock signals.

公开(公告)号：US20180287776A1

公开(公告)日：2018-10-04

申请号：US15907200

申请日：2018-02-27

Applicant: Rambus Inc.

Inventor： Jared L. Zerbe

IPC: H04L7/033 ,  H04L7/00

Abstract: An integrated circuit receiver is disclosed comprising a data receiving circuit responsive to a timing signal to detect a data signal and an edge receiving circuit responsive to the timing signal to detect a transition of the data signal. One of the data or edge receiving circuits comprises an integrating receiver circuit while the other of the data or edge sampling circuits comprises a sampling receiver circuit.

公开(公告)号：US20180157615A1

公开(公告)日：2018-06-07

申请号：US15813963

申请日：2017-11-15

Applicant: Rambus Inc.

Inventor： Mark A. Horowitz ,  Craig E. Hampel ,  Alfredo Moncayo ,  Kevin S. Donnelly ,  Jared L. Zerbe

IPC: G06F13/42 ,  G06F3/06

CPC classification number: G06F13/4291 ,  G06F3/061 ,  G06F3/0611 ,  G06F3/0619 ,  G06F3/0658 ,  G06F3/0661 ,  G06F3/0679 ,  G06F3/0688 ,  G06F12/0246 ,  G06F12/1081 ,  G06F13/102 ,  G06F13/1689 ,  G06F13/364 ,  G06F13/4072 ,  G06F13/4086 ,  G06F13/4234 ,  G06F13/4243 ,  G06F2206/1014 ,  G06F2212/7201 ,  G11C5/04 ,  G11C5/063 ,  G11C7/1048 ,  G11C7/1072 ,  G11C7/22 ,  G11C7/222 ,  G11C16/32 ,  G11C19/00 ,  H03K19/00384 ,  H03K19/018585

Abstract: An integrated circuit device includes a transmitter circuit including an output driver. The integrated circuit device includes a first register to store a value representative of a drive strength setting associated with the transmitter circuit such that the output driver outputs data in accordance with the drive strength setting. The integrated circuit device also includes a second register to store a value representative of an equalization setting associated with the transmitter circuit such that the output driver outputs data in accordance with the equalization setting. The integrated circuit device further includes a third register to store a value representative of a slew rate setting associated with the transmitter circuit such that the output driver outputs data in accordance with the slew rate setting.

公开(公告)号：US20180102923A1

公开(公告)日：2018-04-12

申请号：US15715032

申请日：2017-09-25

Applicant: Rambus Inc.

Inventor： Jared L. Zerbe ,  Vladimir M. Stojanovic ,  Fred F. Chen

IPC: H04L25/03 ,  H04B1/10 ,  H04L7/033 ,  H04L7/00

CPC classification number: H04L25/03019 ,  H04B1/1081 ,  H04L7/0058 ,  H04L7/0087 ,  H04L7/0331 ,  H04L25/03025 ,  H04L25/03038 ,  H04L25/03057 ,  H04L25/03343 ,  H04L25/03885

Abstract: 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.

公开(公告)号：US20180069556A1

公开(公告)日：2018-03-08

申请号：US15644632

申请日：2017-07-07

Applicant: Rambus Inc.

Inventor： Jared L. Zerbe ,  Brian S. Leibowitz ,  Masum Hossain

IPC: H03L7/16 ,  H03L7/24 ,  H03L7/099 ,  H03K5/00 ,  H03L7/06 ,  H03K3/03 ,  H03K5/14 ,  H03K5/13

CPC classification number: H03L7/16 ,  H03J2200/10 ,  H03K3/0315 ,  H03K5/00006 ,  H03K5/13 ,  H03K5/14 ,  H03L7/06 ,  H03L7/0995 ,  H03L7/24

Abstract: In a first clock frequency multiplier, multiple injection-locked oscillators (ILOs) having spectrally-staggered lock ranges are operated in parallel to effect a collective input frequency range substantially wider than that of a solitary ILO. After each input frequency change, the ILO output clocks may be evaluated according to one or more qualifying criteria to select one of the ILOs as the final clock source. In a second clock frequency multiplier, a flexible-injection-rate injection-locked oscillator locks to super-harmonic, sub-harmonic or at-frequency injection pulses, seamlessly transitioning between the different injection pulse rates to enable a broad input frequency range. The frequency multiplication factor effected by the first and/or second clock frequency multipliers in response to an input clock is determined on the fly and then compared with a programmed (desired) multiplication factor to select between different frequency-divided instances of the frequency-multiplied clock.