International Business Machines Corporation

Vinod Ramadurai

Christopher J Gonzalez

Norman Jay Rohrer

Harold Pilo

Rajiv V Joshi

John Edward Barth, Jr

Keunwoo Kim

George Maria Braceras

Mathew I Ringler

Igor Arsovski

Donald W Plass

Chad Allen Adams

Paul David Kartschoke

Gregory J Fredeman

Gerard M Salem

Bao G Truong

Daniel Mark Nelson

Robert Maurice Houle

Michael J Lee

Daryl Michael Seitzer

Stephen Frank Geissler

Abraham Mathews

Steven Harley Lamphier

Miles G Canada

Timothy J Vonreyn

Dongho Lee

Howard Pilo

A single-ended low-swing power-savings mechanism is provided. The mechanism comprises a precharge device that turns off in an evaluation phase and a first biasing device is always on. Within the mechanism, a strength of a keeper device is changed to a first level in response to an input of the second biasing device being at a first voltage level. Within the mechanism the strength of the keeper device is changed to a second level in response to the input of the second biasing device being at a second voltage level. Responsive to receiving a (precharged voltage level read data line signal, a precharged voltage level of the first node falls faster when the keeper device is weakened to a first level. The keeper device turns on in response to receiving a LOW signal and pulls up the voltage at the first node so that a HIGH signal is output.

Single-ended low-swing power-savings mechanism with process compensation

A static random access memory (SRAM) write assist circuit with leakage suppression and level control is described. In one embodiment, the SRAM write assist circuit increases the amount of boost provided in a write cycle, while in another embodiment, the SRAM write assist circuit limits the amount of boost provided at higher supply voltages.

Static random access memory (SRAM) write assist circuit with leakage suppression and level control

A reduced bitline precharge level has been found to increase the SRAM Beta ratio, thus improving the stability margin. The precharge level is also supplied to Sense amplifier, write driver, and source voltages for control signals. In the sense amplifier, the lower precharge voltage compensates for performance loss in the bit-cell by operating global data-line drivers with increased overdrive. In the write driver, the reduced voltage improves the Bitline discharge rate, improves the efficiency of the negative boost write assist, and decreases the reliability exposure of transistors in the write path from negative boost circuit.

Single supply sub VDD bit-line precharge SRAM and method for level shifting

A random access memory circuit enabling a decodable sense amplifier array for power saving with column steering redundancy. A first decoder receives an input address and accesses at least one memory cell in the array and is capable of executing column steering redundancy. A master redundancy signal is triggered when column steering redundancy is requested. A plurality of sense amplifiers, wherein, each sense amplifier in the plurality of sense amplifiers is coupled to at least one memory cell in an array of memory cells. A second decoder receives the input address and selectively activates a first set of sense amplifiers of the plurality of sense amplifiers and selectively activates a second set of sense amplifiers in the plurality of amplifier only when the master redundancy signal is activated.

Structure and method for decoding read data-bus with column-steering redundancy

A memory cell for interconnection with READ and WRITE word lines and READ and WRITE bit lines includes a logical storage element such as a flip-flop formed by a first inverter and a second inverter cross-coupled to the first inverter. The storage element has first and second terminals and a storage element supply voltage terminal configured for interconnection with a first supply voltage. A WRITE access device is configured to selectively interconnect the first terminal to the WRITE bit line under control of the WRITE word line, and a pair of series READ access devices are configured to ground the READ bit line when the READ word line is active and the second terminal is at a high logical level. A logical 'one' can be written to the storage element when a second supply voltage, greater than the first supply voltage, is applied to the WRITE word line, substantially without the use of a complementary WRITE bit line.

Computer program product for designing memory circuits having single-ended memory cells with improved read stability

A selection circuit. The selection circuit comprises a logic circuit, an array of sub-circuits and a switching circuit electrically coupled to each other. The selection circuit is subjected to a first operating condition. The switching circuit selects a group of sub-circuits from the array. The selection circuit generates a first frequency. The selection circuit is subjected to a second operating condition that is different from the first operating condition and generates a second frequency. A first frequency differential between the first frequency and the second frequency is compared to a predetermined frequency differential to determine if the first frequency differential is about equal to the predetermined frequency differential.

Circuit for matching semiconductor device behavior

A design structure embodied in a machine readable medium used in a design process includes a tri-state power gating apparatus for reducing leakage current in a memory array. The apparatus includes a first distributed header device coupled to the memory array, the first distributed header device is configured for limiting leakage current through the memory array; and a header driver operatively coupled to the first distributed header device for enabling tri-state operation of the first distributed header device, wherein tri-state operation includes sleep mode, wake mode, and retention mode.

Design structure for low overhead switched header power savings apparatus

A design structure and method. The design structure comprises a selection circuit comprising a logic circuit, an array of sub-circuits and a switching circuit electrically coupled to each other. The selection circuit is subjected to a first operating condition. The switching circuit selects a group of sub-circuits from the array. The selection circuit generates a first frequency. The selection circuit is subjected to a second operating condition that is different from the first operating condition and generates a second frequency. A first frequency differential between the first frequency and the second frequency is compared to a predetermined frequency differential to determine if the first frequency differential is about equal to the predetermined frequency differential.

Method and circuit for matching semiconductor device behavior

A mechanism is provided for transparent multi-hit correction in associative memories. A content associative memory (CAM) device is provided that transparently and independently executes a precise corrective action in the case of a multiple hit being detected. The wordlines of a CAM array are modified to include a valid bit storage circuit element that indicates whether or not the corresponding wordline is valid or not. In operation, if multiple hits are detected, the multiple hit is signaled to the host system and the particular entries in the CAM array corresponding to the multiple hits are invalidated by setting their associated valid bit storage circuit elements to an invalid value or clearing the value in the associated valid bit storage circuit element. Any data returned to the host system as a result of the multiple hits is invalidated in the host system in response to the signaling of the multiple hits.

Transparent multi-hit correction in associative memories

Methods of operating and designing memory circuits having single-ended memory cells with improved read stability

A static random access memory (SRAM) circuit includes first SRAM cell and a second SRAM cell that are configured to operate in a shared mode and/or an independent mode. In one example, a shared mode includes the sharing of a memory node of a first SRAM cell. In another example, an independent mode includes isolating a first SRAM cell from a second SRAM cell such that they operate independently.

Configurable SRAM system and method

A design structure and method comprising a degradation detection circuit configured to respond to degradation. The degradation detection circuit is located within a semiconductor device and comprises a process sensitive circuit, a measurement circuit, a calculation circuit, and a control circuit. The method comprises subjecting the semiconductor device to a first operating condition. A first value at a first time for a parameter of the process sensitive circuit is measured by the measurement circuit. The semiconductor device is operated to perform an intended function. A second value at a second time for the parameter of the circuit is measured by the measurement circuit. The second time is different from the first time. A first differential value between the first value and the second value is determined by the calculation circuit. The control circuit is configured to receive an enable signal.

Method and circuit for detecting and compensating for a degradation of a semiconductor device

A system for integrating dynamic leakage reduction with a write-assisted SRAM architecture includes power line selection circuitry associated with each column of one or more SRAM sub arrays, controlled by a selection signal that selects the associated sub array for a read or write operation, and by a column write signal that selects one of the columns of the sub arrays. The power line selection circuitry locally converts a first voltage, corresponding to a cell supply voltage for a read operation, to a second lower voltage to be supplied to each cell selected for a write operation, as to facilitate a write function. The power line selection circuitry also locally converts the first voltage to a third voltage to be supplied to power lines in unselected sub arrays, the third voltage also being lower than the first voltage so as to facilitate dynamic leakage reduction.

System and method for integrating dynamic leakage reduction with write-assisted SRAM architecture

A design structure for a static random access memory (SRAM) circuit includes first SRAM cell and a second SRAM cell that are configured to operate in a shared mode and/or an independent mode. In one example, a shared mode includes the sharing of a memory node of a first SRAM cell. In another example, an independent mode includes isolating a first SRAM cell from a second SRAM cell such that they operate independently.

Structure for a configurable SRAM system and method

A method for reducing leakage current in a memory array comprising: coupling a first distributed header device to the memory array, the first distributed header device is configured for limiting leakage current through the memory array; and coupling a header driver operatively to the first distributed header device for enabling tri-state operation of the first distributed header device, wherein tri-state operation includes sleep mode, wake mode, and retention mode.

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South Burlington, VT, United States of America

Vinod Ramadurai