Juniper Networks, Inc.

Praveen Garapally

Srinivas Venkataraman

Anurag P Gupta

Dibyendu K Sen

Srinivas Vaduvatha

Norman Bristol

A system includes a memory and a controller. The controller may include a group of pads and an allocation register. The controller is configured to receive input signals corresponding to the group and allocate each one of the pads to output one of the input signals based on a configuration of pins of the memory. The controller is also configured to redirect the input signals, within the controller, based on the allocation of the pads and output the input signals from the controller into the pads.

Flexible pin allocation

A memory controller includes a circuit to generate a strobe signal for write operations to a DDR SDRAM. The circuit efficiently generates a glitch free strobe signal for a group of data lines. In one implementation, the memory controller includes a write data generation circuits to each transmit a data signal to the memory on a data line, the write data generation circuits being controlled by write enable signals. A write strobe generation circuit generates the strobe signal and the write enable signals, the strobe signal including a preamble window to signal the beginning of the data burst, a data transfer window, and a postamble window to signal the end of the data burst, the write strobe generation circuit generating the write enable signals a half memory cycle early and terminating the write enable signals a half memory cycle late with respect to the data signals generated by the write data generation circuits.

Write strobe generation for a memory interface controller

A memory controller may implement variable delay elements, on a per-bit basis, in both the read and write paths. The memory controller may include multiple adjustable delay circuits associated with data lines and a strobe line, each of the adjustable delay circuits inserting an adjustable amount of delay into a signal destined to or received from one of the data lines or the strobe line. The memory controller may additionally include control logic to determine the delay amount for each of the adjustable delay circuits, the delay amount being determined to reduce static skew between each of the data lines and the strobe line.

Per-bit de-skew mechanism for a memory interface controller

A memory controller, such as a memory controller for reading data received from a DDR SDRAM memory, may detect the beginning and end of a read cycle. The memory controller may include a preamble detection circuit to receive a strobe signal and output a first control signal indicating detection of a preamble window in the strobe signal that indicates a beginning of the read cycle, where the first control signal is delayed based on a selectable delay period applied to the first control signal. The memory controller may further include a first gate to, based on the first control signal, either output the strobe signal for reading of the data lines or block the strobe signal, and the control logic to set an amount of the selectable delay period for the preamble detection circuit.

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Fremont, CA, United States of America

Praveen Garapally