公开(公告)号：US20170126440A1

公开(公告)日：2017-05-04

申请号：US15209454

申请日：2016-07-13

Applicant: Rambus Inc.

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

IPC: H04L25/03

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：US09419825B2

公开(公告)日：2016-08-16

申请号：US14789832

申请日：2015-07-01

Applicant: Rambus Inc.

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

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

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：US09116810B2

公开(公告)日：2015-08-25

申请号：US14333665

申请日：2014-07-17

Applicant: Rambus Inc.

Inventor： Andrew Ho ,  Vladimir Stojanovic ,  Bruno W. Garlepp ,  Fred F. Chen

IPC: G06F11/08 ,  G01R31/317 ,  H04L1/20 ,  H04L1/24 ,  H04L7/033 ,  H04B17/21 ,  H04L7/04 ,  H04L7/10 ,  H04L25/03

CPC classification number: H04B17/29 ,  G01R31/31711 ,  G06F11/08 ,  H04B17/21 ,  H04L1/20 ,  H04L1/241 ,  H04L1/242 ,  H04L7/033 ,  H04L7/043 ,  H04L7/10 ,  H04L25/03006 ,  H04L25/03057 ,  H04L25/03146 ,  H04L25/03949 ,  H04L27/01

Abstract: Described are methods and circuits for margin testing digital receivers. These methods and circuits prevent margins from collapsing in response to erroneously received data, and can thus be used in receivers that employ historical data to reduce intersymbol interference (ISI). Some embodiments detect receive errors for input data streams of unknown patterns, and can thus be used for in-system margin testing. Such systems can be adapted to dynamically alter system parameters during device operation to maintain adequate margins despite fluctuations in the system noise environment due to e.g. temperature and supply-voltage changes. Also described are methods of plotting and interpreting filtered and unfiltered error data generated by the disclosed methods and circuits. Some embodiments filter error data to facilitate pattern-specific margin testing.

公开(公告)号：US09106397B2

公开(公告)日：2015-08-11

申请号：US14616629

申请日：2015-02-06

Applicant: Rambus Inc.

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

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

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：US09000803B2

公开(公告)日：2015-04-07

申请号：US13913156

申请日：2013-06-07

Applicant: Rambus Inc.

Inventor： Vladimir M. Stojanovic ,  Andrew C. Ho ,  Anthony Bessios ,  Fred F. Chen ,  Elad Alon ,  Mark A. Horowitz

IPC: H03K19/0175 ,  H04B1/04 ,  H04L25/02 ,  H04L25/03 ,  H04L25/06 ,  H04L25/49

CPC classification number: H04L25/49 ,  H04B1/04 ,  H04B1/0475 ,  H04B2001/0416 ,  H04L25/025 ,  H04L25/028 ,  H04L25/0282 ,  H04L25/03019 ,  H04L25/03343 ,  H04L25/03885 ,  H04L25/061 ,  H04L25/4917 ,  H04L2025/03363 ,  H04L2025/03802

Abstract: A high-speed signaling system with adaptive transmit pre-emphasis. A transmit circuit has a plurality of output drivers to output a first signal onto a signal path. A receive circuit is coupled to receive the first signal via the signal path and configured to generate an indication of whether the first signal exceeds a threshold level. A first threshold control circuit is coupled to receive the indication from the receive circuit and configured to adjust the threshold level according to whether the first signal exceeds the threshold level. A drive strength control circuit is coupled to receive the indication from the receive circuit and configured to adjust a drive strength of at least one output driver of the plurality of output drivers according to whether the first signal exceeds the threshold level.

公开(公告)号：US20220182158A1

公开(公告)日：2022-06-09

申请号：US17557518

申请日：2021-12-21

Applicant: Rambus Inc.

Inventor： Andrew Ho ,  Vladimir Stojanovic ,  Bruno W. Garlepp ,  Fred F. Chen

IPC: H04B17/29 ,  H04L25/03 ,  H04L27/01 ,  H04B17/21 ,  G01R31/317 ,  H04L1/20 ,  H04L1/24 ,  H04L7/033 ,  G06F11/08

Abstract: Described are methods and circuits for margin testing digital receivers. These methods and circuits prevent margins from collapsing in response to erroneously received data and can thus be used in receivers that employ historical data to reduce intersymbol interference (ISI). Some embodiments detect receive errors for input data streams of unknown patterns and can thus be used for in-system margin testing. Such systems can be adapted to dynamically alter system parameters during device operation to maintain adequate margins despite fluctuations in the system noise environment due to e.g. temperature and supply-voltage changes. Also described are methods of plotting and interpreting filtered and unfiltered error data generated by the disclosed methods and circuits. Some embodiments filter error data to facilitate pattern-specific margin testing.

公开(公告)号：US20210051047A1

公开(公告)日：2021-02-18

申请号：US17000191

申请日：2020-08-21

Applicant: Rambus Inc.

Inventor： Vladimir M. Stojanovic ,  Andrew C. Ho ,  Anthony Bessios ,  Fred F. Chen ,  Elad Alon ,  Mark A. Horowitz

IPC: H04L25/49 ,  H04L25/02 ,  H04L25/03 ,  H04L25/06 ,  H04B1/04

Abstract: A high-speed signaling system with adaptive transmit pre-emphasis. A transmit circuit has a plurality of output drivers to output a first signal onto a signal path. A receive circuit is coupled to receive the first signal via the signal path and configured to generate an indication of whether the first signal exceeds a threshold level. A first threshold control circuit is coupled to receive the indication from the receive circuit and configured to adjust the threshold level according to whether the first signal exceeds the threshold level. A drive strength control circuit is coupled to receive the indication from the receive circuit and configured to adjust a drive strength of at least one output driver of the plurality of output drivers according to whether the first signal exceeds the threshold level.

公开(公告)号：US10735116B2

公开(公告)日：2020-08-04

申请号：US16228470

申请日：2018-12-20

Applicant: Rambus Inc.

Inventor： Andrew Ho ,  Vladimir Stojanovic ,  Bruno W. Garlepp ,  Fred F. Chen

IPC: H04B17/29 ,  H04L1/20 ,  H04L1/24 ,  H04L25/03 ,  H04B17/21 ,  G01R31/317 ,  H04L27/01 ,  H04L7/033 ,  G06F11/08 ,  H04L7/04 ,  H04L7/10

Abstract: Described are methods and circuits for margin testing digital receivers. These methods and circuits prevent margins from collapsing in response to erroneously received data and can thus be used in receivers that employ historical data to reduce intersymbol interference (ISI). Some embodiments detect receive errors for input data streams of unknown patterns and can thus be used for in-system margin testing. Such systems can be adapted to dynamically alter system parameters during device operation to maintain adequate margins despite fluctuations in the system noise environment due to e.g. temperature and supply-voltage changes. Also described are methods of plotting and interpreting filtered and unfiltered error data generated by the disclosed methods and circuits. Some embodiments filter error data to facilitate pattern-specific margin testing.

公开(公告)号：US10205614B2

公开(公告)日：2019-02-12

申请号：US16010445

申请日：2018-06-16

Applicant: Rambus Inc.

Inventor： Jared L. Zerbe ,  Fred F. Chen ,  Andrew Ho ,  Ramin Farjad-Rad ,  John W. Poulton ,  Kevin S. Donnelly ,  Brian S. Leibowitz ,  Vladimir Stojanovic

IPC: H04L27/01 ,  H04L25/03 ,  H04L25/497 ,  H04W52/20 ,  H04L1/00 ,  H04L7/033 ,  H04L25/02 ,  H04L7/00 ,  H04W52/22

Abstract: A signaling system includes a pre-emphasizing transmitter and an equalizing receiver coupled to one another via a high-speed signal path. The receiver measures the quality of data conveyed from the transmitter. A controller uses this information and other information to adaptively establish appropriate transmit pre-emphasis and receive equalization settings, e.g. to select the lowest power setting for which the signaling system provides some minimum communication bandwidth without exceeding a desired bit-error rate.

公开(公告)号：US20180367350A1

公开(公告)日：2018-12-20

申请号：US16010445

申请日：2018-06-16

Applicant: Rambus Inc.

Inventor： Jared L. Zerbe ,  Fred F. Chen ,  Andrew Ho ,  Ramin Farjad-Rad ,  John W. Poulton ,  Kevin S. Donnelly ,  Brian S. Leibowitz

IPC: H04L27/01 ,  H04L25/03 ,  H04L1/00 ,  H04L7/033 ,  H04L25/497 ,  H04W52/20 ,  H04L7/00 ,  H04L25/02 ,  H04W52/22

CPC classification number: H04L27/01 ,  H04L1/0026 ,  H04L7/0025 ,  H04L7/0087 ,  H04L7/0337 ,  H04L25/0272 ,  H04L25/028 ,  H04L25/03057 ,  H04L25/03343 ,  H04L25/03885 ,  H04L25/497 ,  H04L2025/03503 ,  H04W52/20 ,  H04W52/225 ,  Y02D70/00

Abstract: A signaling system includes a pre-emphasizing transmitter and an equalizing receiver coupled to one another via a high-speed signal path. The receiver measures the quality of data conveyed from the transmitter. A controller uses this information and other information to adaptively establish appropriate transmit pre-emphasis and receive equalization settings, e.g. to select the lowest power setting for which the signaling system provides some minimum communication bandwidth without exceeding a desired bit-error rate.