Rambus Inc.

Sivakumar Doraiswamy

Benedict C Lau

Jade M Kizer

Huy M Nguyen

Vijay Gadde

An integrated circuit (IC) memory controller is disclosed. The memory controller includes a receiver to receive a strobe signal and provide an internal strobe signal. An adjustable delay circuit delays an enable signal to generate a delayed enable signal. A gate circuit generates a gated strobe signal using the delayed enable signal that masks transitions of the internal strobe signal that occur prior to a valid region of the internal strobe signal. A sample circuit samples data using the gated strobe signal.

Memory controller for strobe-based memory systems

Described are amplifiers that facilitate high-speed communication with calibrated drive strength and termination impedance. Drivers and termination elements can be divided into a number N of parallel portions, one or more of which can be disabled and updated without interfering with signal (e.g., clock or data) transmission. Some embodiments identify inactive elements by examining incoming signals.

Driver calibration methods and circuits

A memory controller for strobe-based memory systems is disclosed. The memory controller includes a circuit to generate a control signal having a predetermined timing relationship with respect to a first clock signal, a circuit to receive the control signal, and a receiver to sample the read data in response to the qualified read strobe signal. The receiving circuit includes an input to receive an external read strobe signal transmitted by a semiconductor memory device, circuitry to synchronize the control signal and the received read strobe signal to have a common timing relationship with respect to each other, and circuitry to gate the read strobe signal based on the synchronized control signal.

A method of calibrating read operations in a memory system is disclosed. The method involves placing a memory controller in a calibration mode, and performing a series of dummy read operations. Each of the read operations performs a read of pre-specified data stored in at least one memory component while using different ones of delayed enable signals. Data read from respective dummy read operations is compared to identify successful read operations while the timing information from successful read operations is compared to identify a suitable delayed enable signal.

Method for calibrating read operations in a memory system

Systems and methods for masking strobe signals in strobe-based systems are provided below. These strobe-masking systems receive a strobe signal from a component operating under one clock domain and in turn generate a masked version of the strobe signal. Components of a host system use the masked strobe signal to receive or transfer data from the clock domain of the strobe signal through a mesochronous clock domain crossing into a different clock domain.

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San Jose, CA, United States of America

Sivakumar Doraiswamy