Cadence Design Systems, Inc.

Aaron Willey

Thomas Evan Wilson

H Md Shuaeb Fazeel

Hari Anand Ravi

Nikhil Sawarkar

Vinod Kumar

Sachin Ramesh Gugwad

Moo Sung Chae

Balbeer Rathor

Disclosed is an improved approach for a training approach to implement DFE for an electronic circuit. The inventive concept is particularity suitable to address, for example, circuits that implement high speed parallel data transmission protocols, such as GDDR6, that are used for graphics applications. The training scheme uses minimal hardware when compared to existing schemes by reusing calibration receiver in auto zeroing receiver as error receiver. Further it works for closed eyes by running the algorithm multiple times with gradual increase in complexity of training pattern, where DFE coefficients from previous iteration is used for the current iteration, thereby gradually opening the eye.

Hardware efficient decision feedback equalization training

Circuits, methods and systems that are to be used for dynamically modulating a high frequency bit duration of data based on a status of one or more previous transmitted bits. One circuit comprises a first data path comprising a first input, a first buffer, and a first output connected to a first multiplexer data input. The circuit further comprises a second data path comprising a second input, a second buffer, a phase interpolator, and a second output coupled to a second multiplexer data input. The circuit further comprises a multiplexer having at least two data inputs, at least one control input, and a common output coupled to a transmitter signal line and wherein the at least one control input is operatively coupled to a generated control signal that is based on the status of one or more previous transmitted bits.

Time based feed forward equalization (TFFE) for high-speed DDR transmitter

Embodiments relate to systems, methods, and computer-readable media to enable design and creation of receiver circuitry. One embodiment is a receiver apparatus comprising a plurality of receiver arrangements, each receiver arrangement having a sampling circuit and a multi-stage differential amplifier connected to the sampling circuit. Each receiver arrangement is configurable via switches between an amplifying mode and an autozero mode. Control circuitry may select output data from a sampling circuit of one or more receiver arrangements that are not in autozero mode. In various embodiments, settings for individual receiver arrangements may be set based on decision feedback equalization (DFE).

High-speed low VT drift receiver

Embodiments described herein relate to circuits and techniques for interfacing a microprocessor with memory devices, particularly memory devices such as DDR SDRAM in accordance with protocols such as DDR4 and DDR5. Some embodiments particularly relate to a receiver architecture for a DDR memory interface device that provides AC coupling to memory and includes auto-zeroing functionality. These and other embodiments incorporate equalization functionality such as decision feedback equalization and continuous time linear equalization.

Auto-zeroing receiver for memory interface devices

Embodiments relate to systems, methods, and computer-readable media to enable design and creation of receiver circuitry. One embodiment is a receiver apparatus comprising a plurality of receiver arrangements, each receiver arrangement having a sampling circuit and a multi-stage differential amplifier connected to the sampling circuit. Each receiver arrangement is configurable via switches between an amplifying mode and an autozero mode. Control circuitry may select output data from receiver arrangements that are not in autozero mode using multiplexer circuitry. In various embodiments, settings for individual receiver arrangements may be set based on decision feedback equalization (DFE).

Growing community of inventors

Hayward, CA, United States of America

Aaron Willey