Advanced Micro Devices Corporation

Globalfoundries Inc.

Rohit Kumar

Gerald Robert Talbot

Emerson S Fang

Paul C Miranda

Larry David Hewitt

Dennis M Fischette, Jr

Sai V Vishwanthaiah

Ross Voigt La Fetra

Anand Daga

Sanjay Sethi

Stephen C Hale

A technique for characterizing a communications interface includes determining a voltage margin and a timing margin of the interface based on data sampled by a sampling device of a receiver of the interface. In at least one embodiment of the invention, a method for determining margin associated with a receiver circuit of an integrated circuit includes periodically sampling a signal over a time period by a receiver sampling circuit of the receiver circuit to generate a sampled version of the signal. The method includes incrementally varying a value of the parameter associated with the signal. The varying of the parameter is through a range of values of the parameter over the time period. The method includes determining a margin value of the receiver circuit associated with the parameter based, at least in part, on the sampled version of the signal.

Transmitter voltage and receiver time margining

A method and mechanism for reducing lock time of a dual-path phase lock loop (PLL). The PLL comprises a dual-path low-pass filter (LPF). The LPF includes a first filter and a second filter. The first filter comprises a passive second-order lead-lag low-pass filter. The second filter comprises a first-order lag low-pass filter. During a lock-acquisition state, an impedance value within the second stage is bypassed, which increases the loop bandwidth of the PLL. In addition, a resistance within the first stage is increased in order to increase the gain of the first stage and maintain stability within the PLL. During a lock state, the impedance value may no longer be bypassed and the increased resistance may be returned to its original value.

Method to decrease locktime in a phase locked loop

An in-band configuration technique configures a data communications link for high-speed data communications between at least a first and second integrated circuit using in-band communications between the first and second integrated circuits. The technique configures at least one equalizer of the data communications link with predetermined equalizer settings selected from a plurality of predetermined equalizer settings based on a selected rate of data communications for the link.

In-band method to configure equalization levels

A driver circuit that consumes less current than other driver circuits combines a current-mode driver circuit with a voltage-mode driver circuit to provide impedance matching and signal equalization operations. In at least one embodiment of the invention, an apparatus includes a differential node and a driver circuit configured to generate a signal on the differential node. The driver circuit includes a first circuit portion configured to generate a first signal on the differential node based, at least in part, on a data signal. The first signal has a voltage swing based, at least in part, on a voltage on a power supply node. The driver circuit includes at least a second circuit portion configured to generate a current through the differential node based, at least in part, on a first bit-time of the data signal and an equalization operation, thereby adjusting the voltage swing of the signal.

Hybrid output driver for high-speed communications interfaces

An integrated circuit includes at least a first and second compensation circuit that compensate for process, temperature, and other variable conditions that affect circuit performance. A compensation select circuit is coupled to selectively enable each of the first and second compensation circuits at respective first and second time periods to control a voltage on the input/output terminal to substantially equal a reference voltage and thereby determine appropriate compensation setting.

Method and apparatus for sharing an input/output terminal by multiple compensation circuits

A voltage controlled delay line (VCDL). The VCDL includes one or more cells. Each of the one or more cells includes two or more inputs and an output. Each of the one or more cells is configured to provide a delay as well as an interpolation function and a multiplexer function. The VCDL may be used to provide delay in a delay locked loop (DLL).

Voltage controlled delay line (VCDL) having embedded multiplexer and interpolation functions

A driver circuit. In one embodiment, the driver circuit includes a plurality of pull-up circuits and a plurality of pull-down circuits. The driver circuit also includes control logic that is coupled to activate/deactivate the pull-up and pull-down circuits. The driver circuit may perform emphasized signal transmissions having a voltage swing of a first magnitude or de-emphasized signal transmissions having a voltage swing of a second magnitude, wherein the first magnitude is greater than the second magnitude. The control logic is further configured to activate and/or deactivate pull-up and/or pull-down circuits such that the driver circuit output impedance in the emphasized mode is substantially equal to the output impedance in the de-emphasized mode.

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San Jose, CA, United States of America

Rohit Kumar