Rambus Inc.

Andrew C C Ho

Mark A Horowitz

Vladimir Marko Stojanovic

Anthony G Bessios

Bruno Werner Garlepp

Jared L Zerbe

Jason C Wei

Grace Tsang

Fred F Chen

Elad Alon

Marc A Horowitz

A signaling system is described. The signaling system comprises a transmit device, a receive device including a partial response receive circuit, and a signaling path coupling the transmit device and the receive device. The receive device observes an equalized signal from the signaling path, and includes circuitry to use feedback from the most recent previously resolved symbol to sample a currently incoming symbol. The transmit device equalizes transmit data to transmit the equalized signal, by applying weighting based on one or more data values not associated with the most recent previously resolved symbol value.

Partial response receiver

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.

High speed signaling system with adaptive transmit pre-emphasis

Equalizing receiver

A receive circuit for receiving a signal transmitted via an electric signal conductor. A first sampling circuit generates a first sample value that indicates whether the signal exceeds a first threshold level, and a second sampling circuit generates a second sample value that indicates whether the signal exceeds a second threshold level. A first select circuit receives the first and second sample values from the first and second sampling circuits and selects, according to a previously generated sample value, either the first sample value or the second sample value to be output as a selected sample value.

An integrated circuit device having a receive circuit is disclosed. The receive circuit generates first and second sets of samples of incoming symbols during first and second time intervals, respectively. A select circuit selects, based at least in part on the first set of samples, at least one sample from the second set to be output as a received data value. The integrated circuit device further includes a transmit circuit to generate an output symbol during a third time interval. The output symbol has an amplitude based, at least in part, on a transmit data value for which an output symbol was generated during a time interval prior to the third time interval.

A differential amplifier and method of using same are disclosed. In one particular exemplary embodiment, the present invention may be realized as a circuit comprising a differential amplifier for receiving a differential input signal and generating a differential output signal, a comparator for generating an adjustment signal based at least in part upon the differential output signal, and a current controller for controlling current steering and at least one offset current in the differential amplifier based at least in part upon the adjustment signal and a current steering variable signal.

Differential amplifiers and methods of using same

A signaling system having first and second sampling circuits and an output driver circuit. The first sampling circuit samples a first signal generated by the output driver circuit to determine whether the first signal exceeds a first threshold. The second sampling circuit samples the first signal to determine whether the first signal exceeds a second threshold. The drive strength of the output driver circuit is adjusted based, at least in part, on whether the first signal exceeds the first and second thresholds, and the second threshold is adjusted based, at least in part, on whether the first signal exceeds the second threshold.

Growing community of inventors

Palo Alto, CA, United States of America

Andrew C C Ho