International Business Machines Corporation

Globalfoundries Inc.

Globalfoundries U.S. 2 LLC

Robert Maurice Houle

Igor Arsovski

Michael Thomas Fragano

Rajiv V Joshi

Harold Pilo

Kevin A Batson

George Maria Braceras

Thomas M Maffitt

Robert Louis Franch

Kenneth Michael Zick

Sebastian Theodore Ventrone

John Atkinson Fifield

Kevin William Gorman

Gerard M Salem

Robert E Busch

Vinod Ramadurai

Stephen Frank Geissler

Steven Harley Lamphier

Mathew I Ringler

Miles G Canada

Kenneth Torino

Akhilesh Patil

Dac C Pham

Timothy J Vonreyn

David K Balkin

Dongho Lee

Van D Butler

The present disclosure relates to a pre-charge circuit including a first inverter which receives an early pre-charge signal and outputs an inverted early pre-charge signal, a first gate which receives a late pre-charge signal and a match line output signal and outputs an AND output signal, and a second gate which receives the inverted early pre-charge signal and the AND output signal and outputs an effective pre-charge signal.

Ternary content addressable memory (TCAM) for multi bit miss detect circuit

The present disclosure relates to a content addressable memory (CAM), and more particularly, to an algorithmic ternary content addressable memory (TCAM) that instantiates multiple copies of X-Y TCAMs. The structure includes a content addressable memory (CAM) and an array which instantiates multiple replicated copies of the CAM in a row direction and a column direction of the array.

Algorithmic N search/M write ternary content addressable memory (TCAM)

Words of data are maintained in content-addressable memory cells arranged in rows. Two of the rows are timing reference rows, and the remainder of the rows are data rows that maintain the words of data. The data rows form individual matchlines. A first of the reference rows forms a precharge reference matchline, and a second of the reference rows forms an evaluation reference matchline. The timing for the individual matchlines to precharge is based on the time to precharge the precharge reference matchline, and timing for the individual matchlines to evaluate a search word is based on the time for the evaluation reference matchline to evaluate the search word.

Content-addressable memory having multiple reference matchlines to reduce latency

The present disclosure relates to content addressable memories (CAM), and more particularly, to a searchable CAM structure having self-reference matchline precharge and local feedback control and method of use. The present disclosure includes a structure which includes: a sense line connected to a sensing device; a feedback line connected to the sense line at a tap point between a first end and a second end of the sense line; and a local precharge controller connected to the tap point by the feedback line to control precharging of the sense line according to a state of the feedback line.

Matchline precharge architecture for self-reference matchline sensing

Methods and structures for configuring an integrated circuit including repeated cells that are divided into banks having a respective power assist and a respective operational assist are provided. A method includes configuring the banks without power assist and operational assist. The method further includes selecting the power assist for a bank based on a determination that a weak cell remains in the bank after configuring the bank with the respective operational assist.

Majority dominant power scheme for repeated structures and structures thereof

An approach for providing fine granularity power gating of a memory array is described. In one embodiment, power supply lines are disposed in a horizontal dimension of the memory array parallel to the word lines that access cells arranged in rows and columns of the array, wherein each of the supply lines are shared by adjacent cells in the memory. Power supply lines that activate a row selected by one of the word lines are supplied a full-power voltage value and power supply lines that activate rows adjacent to the selected row are supplied a half-power voltage value, while the power supply lines of the remaining rows in the memory array are supplied a power-gated voltage value.

Fine granularity power gating

Methods of setting wordline up-level voltage in as-fabricated SRAM. In one example, the method includes determining the relative speed, or strength, of 1) the combination of the pass-gate and pull-down devices and 2) the pull-up devices in the bitcells of the SRAM. These relative strengths are then used to adjust the wordline up-level voltage, if needed, to decrease the likelihood of the SRAM experiencing a stability failure. Corresponding systems are provided for determining the relative strengths of the devices of interest, for determining the amount of up-level voltage adjustment needed, and for selecting and setting the up-level voltage.

Methods and systems for adjusting wordline up-level voltage to improve production yield relative to SRAM-cell stability

An SRAM delay circuit that tracks bitcell characteristics. A circuit is disclosed that includes an input node for receiving an input signal; a reference node for capturing a reference current from a plurality of reference cells; a capacitance network having a discharge that is controlled by the reference current; and an output circuit that outputs the input signal with a delay, wherein the delay is controlled by the discharge of the capacitance network.

SRAM delay circuit that tracks bitcell characteristics

An integrated circuit that includes memory containing wordlines and bitcells having SRAM storage elements and being connected to the wordlines. Wordline up-level assist circuitry is provided that is designed and configured to provide a plurality of selectable voltage values that can be selected to provide the wordline up-level voltage that is provided to the bitcells during a memory read cycle and/or write cycle. In one example, the voltage value selected is selected based on characterization of the as-fabricated bitcells so as to decrease the likelihood of the bitcells experiencing a stability failure.

SRAM having wordline up-level voltage adjustable to assist bitcell stability and design structure for same

An apparatus and method for low power, single-ended sensing in a multi-port static random access memory (SRAM) using pre-discharged bit lines includes holding a bit line associated with the memory cell at a zero voltage potential when the memory cell is not being accessed; releasing the bit line from being held at a zero voltage potential when the memory cell is being accessed; charging the bit line to a first voltage potential greater in value than the zero voltage potential during an access of the memory cell, wherein charging the bit line to a first voltage potential occurs for a first predetermined period of time after access to the memory cell has begun; and sensing the memory cell contents during an access of the memory cell, wherein sensing of the memory cell contents occurs for a second predetermined period of time after access to the memory cell has begun.

Low power, single-ended sensing in a multi-port SRAM using pre-discharged bit lines

A method and circuit for measuring internal pulses includes an enable circuit configured to receive a control signal from an on-chip built-in tester to enable measurement of internal circuits. A delay chain is configured to receive a pulse signal from an on-chip circuit component. Sampling latches each include a data input coupled between adjacent delay elements of the delay chain and synchronized with the clock signal such that a transition in the pulse signal is indicated by comparing adjacent digital values in an output sequence.

Method and apparatus for calibrating internal pulses in an integrated circuit

A method for sensing the contents of a memory cell within a static random access memory (SRAM) includes holding a bit line associated with the memory cell at a zero voltage potential when the memory cell is not being accessed; energizing the bit line to a first voltage potential different than the zero voltage potential during an access of the memory cell; and sensing the memory cell contents when the associated bit line has reached the first voltage potential.

Method for low power sensing in a multi-port SRAM using pre-discharged bit lines

A local on-chip programmable pulsewidth and delay generating circuit includes a clock generation circuit configured to receive a global clock signal and output a local clock signal. The clock generation circuit includes a pulse shaping portion which adjusts a pulse width of the global clock signal in accordance with at least one of a trailing edge delay and a leading edge delay. The leading edge delay is generated by a leading edge delay circuit, and the trailing edge delay is generated by a trailing edge delay circuit configured to apply a delay to a trailing edge of a pulse. The trailing edge delay circuit includes a delay chain having programmable stages of delay elements, each stage being independently controlled using control bits decoded from address latches.

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Williston, VT, United States of America

Robert Maurice Houle