Patent application number | Description | Published |
20080278992 | INDEPENDENT-GATE CONTROLLED ASYMMETRICAL MEMORY CELL AND MEMORY USING THE CELL - Techniques are provided for employing independent gate control in asymmetrical memory cells. A memory circuit, such as an SRAM circuit, can include a number of bit line structures, a number of word line structures that intersect the bit line structures to form a number of cell locations, and a number of asymmetrical memory cells located at the cell locations. Each of the asymmetrical cells can be selectively coupled to a corresponding one of the bit line structures under control of a corresponding one of the word line structures. Each of the cells can include a number of field effect transistors (FETS), and at least one of the FETS can be configured with separately biased front and back gates. One gate can be biased separately from the other gate in a predetermined manner to enhance read stability of the asymmetrical cell. | 11-13-2008 |
20080315907 | Methods of Operating an Electronic Circuit for Measurement of Transistor Variability and the Like - An electronic circuit includes an output terminal and at least a first measuring FET. The second drain-source terminals of a plurality of FETS to be tested are interconnected with the first drain-source terminal of the first measuring FET and the output terminal. The second drain-source terminal of the first measuring FET is interconnected with a first biasing terminal. The first drain-source terminals of the FETS to be tested are interconnected with a second biasing terminal. A state machine is coupled to the gates of the FETS to be tested and the gate of the first measuring FET. The state machine is configured to energize the gate of the first measuring FET and to sequentially energize the gates of the FETS to be tested, so that an output voltage appears on the output terminal. Circuitry to compare the output voltage to a reference value is also provided. The gate of the first measuring field effect transistor is energized; the gates of the field effect transistors to be tested are sequentially energized, whereby an output voltage appears on the output terminal; and the output voltage is compared to the reference value. | 12-25-2008 |
20090067223 | COMPUTER-READABLE MEDIUM ENCODING A BACK-GATE CONTROLLED ASYMMETRICAL MEMORY CELL AND MEMORY USING THE CELL - Techniques are provided for back-gate control in an asymmetrical memory cell. In one aspect, the cell includes five transistors and can be employed for static random access memory (SRAM) applications. An inventive memory circuit can include a plurality of bit line structures, a plurality of word line structures that intersect the plurality of bit line structures to form a plurality of cell locations, and a plurality of cells located at the plurality of cell locations. Each cell can be selectively coupled to a corresponding one of the bit line structures under control of a corresponding one of the word line structures. Each cell can include a first inverter having first and second field effect transistors (FETS) and a second inverter with third and fourth FETS that is cross-coupled to the first inverter to form a storage flip-flop. One of the FETS in the first inverter can be configured with independent front and back gates and can function as both an access transistor and part of one of the inverters. | 03-12-2009 |
20090147592 | Memory Circuit with Decoupled Read and Write Bit Lines and Improved Write Stability - In a memory circuit, data from all cells along a selected word line is read. Then, the read data is written back to half-selected cells and new data is written to the selected cells in the next cycle. In cases where a READ bit line (RBL) and WRITE bit line (WBL) are decoupled, RBL and WBL can be accessed simultaneously. Hence, the WRITE in the n-th cycle can be delayed to the n+1-th cycle as far as there is no data hazard such as reading data from memory before correct data are actually written to memory. As a result, there is no bandwidth loss, although the latency of the WRITE operation increases. WRITE stability issues in previous configurations with decoupled RBL and WBL are thus addressed. | 06-11-2009 |
20090309625 | ELECTRONIC CIRCUIT FOR MEASUREMENT OF TRANSISTOR VARIABILITY AND THE LIKE - An electronic circuit includes an output terminal and at least a first measuring FET. The second drain-source terminals of a plurality of FETS to be tested are interconnected with the first drain-source terminal of the first measuring FET and the output terminal. The second drain-source terminal of the first measuring FET is interconnected with a first biasing terminal. The first drain-source terminals of the FETS to be tested are interconnected with a second biasing terminal. A state machine is coupled to the gates of the FETS to be tested and the gate of the first measuring FET. The state machine is configured to energize the gate of the first measuring FET and to sequentially energize the gates of the FETS to be tested, so that an output voltage appears on the output terminal. Circuitry to compare the output voltage to a reference value is also provided. The gate of the first measuring field effect transistor is energized; the gates of the field effect transistors to be tested are sequentially energized, whereby an output voltage appears on the output terminal; and the output voltage is compared to the reference value. | 12-17-2009 |
20120081141 | On-Chip Delay Measurement Through a Transistor Array - Methods and apparatus are provided for measuring a delay through one or more transistors in an array of transistors. The delay through one or more transistors in an array of transistors is measured by selecting one of the transistors in the array; and applying a clock signal to the selected transistor, wherein an output of the selected transistor is applied to a first input of a logic gate having at least two inputs and wherein a second clock signal based on the clock signal is applied to a second input of the logic gate, and wherein an output of the logic gate indicates a difference in arrival times of the signals at the two inputs. In one variation, a clock signal is applied to the selected transistor and a variable delay circuit; and an output of the selected transistor is applied to a data input of a latch having a clock input and a data input while an output of the variable delay circuit is applied to a clock input of the latch. The delay applied by the variable delay circuit to the clock signal is adjusted until a predefined transition is detected in an output of the latch. If the delay is measured through a plurality of transistors in the array, the delay variation among the plurality of transistors can be obtained. | 04-05-2012 |
20130049824 | 3D CHIP STACK SKEW REDUCTION WITH RESONANT CLOCK AND INDUCTIVE COUPLING - There is provided a clock distribution network for synchronizing global clock signals within a 3D chip stack having two or more strata. The clock distribution network includes a plurality of clock distribution circuits, each being arranged on a respective one of the two or more strata for providing the global clock signals to various chip locations. Each of the plurality of clock distribution circuits includes a resonant circuit for providing stratum-to-stratum coupling for the clock distribution network. The resonant circuit includes at least one capacitor and at least one inductor. | 02-28-2013 |
20130212414 | REDUCING PERFORMANCE DEGRADATION IN BACKUP SEMICONDUCTOR CHIPS - A system has at least a first circuit portion and a second circuit portion. The first circuit portion is operated at normal AC frequency. The second circuit portion is operated in a back-up mode at low AC frequency, such that the second circuit portion can rapidly come-online but has limited temperature bias instability degradation. The second circuit portion can then be brought on-line and operated at the normal AC frequency. A system including first and second circuit portions and a control unit, as well as a computer program product, are also provided. | 08-15-2013 |
20130253868 | ESTIMATING DELAY DETERIORATION DUE TO DEVICE DEGRADATION IN INTEGRATED CIRCUITS - A method for estimating delay deterioration in an integrated circuit comprising estimating degradation in at least one characteristic of each device defined within the integrated circuit using voltages and logic values monitored during a simulation of the digital circuit. Generating an end-of-life netlist in which the at least one device characteristic of each device has been modified to reflect the estimated degradation or estimating a change in timing delay of each device directly from the estimated degradation of the at least one characteristic of each device. Performing a timing analysis using the estimated change in timing delay of each device to determine circuit path delays. The timing analysis being static or statistical. | 09-26-2013 |
20130254731 | ESTIMATING DELAY DETERIORATION DUE TO DEVICE DEGRADATION IN INTEGRATED CIRCUITS - A method for estimating delay deterioration in an integrated circuit comprising estimating degradation in at least one characteristic of each device defined within the integrated circuit using voltages and logic values monitored during a simulation of the digital circuit. Generating an end-of-life netlist in which the at least one device characteristic of each device has been modified to reflect the estimated degradation or estimating a change in timing delay of each device directly from the estimated degradation of the at least one characteristic of each device. A timing analysis is performed using the estimated change in timing delay of each device to determine circuit path delays. The timing analysis is static or statistical. | 09-26-2013 |
20130258750 | DUAL-CELL MTJ STRUCTURE WITH INDIVIDUAL ACCESS AND LOGICAL COMBINATION ABILITY - A dual-cell spin-transfer torque random-access memory including a first magnetic tunneling junction and a second magnetic tunneling junction. An access circuit is coupled to the first and second magnetic tunneling junctions such that independent read and write access is provided to bits stored in the first and second magnetic tunneling junctions. | 10-03-2013 |
20140013131 | POWER NAPPING TECHNIQUE FOR ACCELERATED NEGATIVE BIAS TEMPERATURE INSTABILITY (NBTI) AND/OR POSITIVE BIAS TEMPERATURE INSTABILITY (PBTI) RECOVERY - A logic circuit is operated in a normal mode, with a supply voltage coupled to a supply rail of the logic circuit, and with a ground rail of the logic circuit grounded; It is determined that at least a portion of the logic circuit has experienced degradation due to bias temperature instability. Responsive to the determining, the logic circuit is operated in a power napping mode, with the supply voltage coupled to the ground rail of the circuit, with the supply rail of the circuit grounded, and with primary inputs of the circuit toggled between logical zero and logical one at low frequency. A logic circuit and corresponding design structures are also provided. | 01-09-2014 |
20140372797 | PULSED-LATCH BASED RAZOR WITH 1-CYCLE ERROR RECOVERY SCHEME - Systems and methods for error recovery include determining an error in at least one stage of a plurality of stages during a first cycle on a hardware circuit, each of the plurality of stages having a main latch and a shadow latch. A first signal is transmitted to an output stage of the at least one stage to stall the main latch and the shadow latch of the output stage during a second cycle. A second signal is transmitted to an input stage of the at least one stage to stall the main latch of the input stage during the second cycle and to stall the main latch and the shadow latch of the input stage during a third cycle. Data is restored from the shadow latch to the main latch for the at least one stage and the input stage to recover from the error. | 12-18-2014 |
Patent application number | Description | Published |
20090018787 | APPARATUS AND METHOD FOR DETERMINING THE SLEW RATE OF A SIGNAL PRODUCED BY AN INTEGRATED CIRCUIT - Determining a slew rate of a signal from an integrated circuit under test by comparing the signal with a first reference voltage, comparing the signal with a second reference voltage different from the first reference voltage, generating an output pulse having a pulse width indicative of a slew rate of the signal, and integrating the output pulse over time to generate an output voltage proportional to the pulse width; wherein the output voltage is indicative of the slew rate of the signal produced by the integrated circuit. | 01-15-2009 |
20090091346 | CIRCUITS AND METHODS FOR CHARACTERIZING DEVICE VARIATION IN ELECTRONIC MEMORY CIRCUITS - A circuit includes a comparator circuit configured such that its output toggles from a first digital logical level to a second digital logical level when its first and second inputs transition between a first state wherein the first input has an applied voltage greater than an applied voltage at the second input and a second state wherein the first input has an applied voltage less than an applied voltage at the second input. A plurality of cells each have at least one series-connected pair of field effect transistors interconnected at an output node intermediate the field effect transistors. Decoding logic is configured to select a given one of the cells for measurement, and selectively interconnect the output node of the given one of the cells to the first input of the comparator circuit. Voltage supply circuitry is configured to (i) apply voltages to the gates of the pair of transistors of the given one of the cells selected for measurement, such that the pair of transistors operate in a linear region, and have a variable voltage difference, Δ, between their gate-to-source voltages, and (ii) vary the Δ until the comparator circuit output toggles from the first digital logical level to the second digital logical level. | 04-09-2009 |
20090185409 | ENHANCED STATIC RANDOM ACCESS MEMORY STABILITY USING ASYMMETRIC ACCESS TRANSISTORS AND DESIGN STRUCTURE FOR SAME - A memory circuit includes a plurality of bit line structures (each including a true and a complementary bit line), a plurality of word line structures intersecting the plurality of bit line structures to form a plurality of cell locations and a plurality of cells located at the plurality of cell locations. Each of the cells includes a logical storage element, a first access transistor selectively coupling a given one of the true bit lines to the logical storage element, and a second access transistor selectively coupling a corresponding given one of the complementary bit lines to the logical storage element. One or both of the first and second access transistors are configured with asymmetric current characteristics to enable independent enhancement of READ and WRITE margins. Also included within the | 07-23-2009 |
20090189703 | CIRCUITS AND DESIGN STRUCTURES FOR MONITORING NBTI (NEGATIVE BIAS TEMPERATURE INSTABILITY) EFFECT AND/OR PBTI (POSITIVE BIAS TEMPERATURE INSTABILITY) EFFECT - A ring oscillator has an odd number of NOR-gates greater than or equal to three, each with first and second input terminals, a voltage supply terminal, and an output terminal. The first input terminals of all the NOR-gates are interconnected, and each of the NOR-gates has its output terminal connected to the second input terminal of an immediately adjacent one of the NOR-gates. During a stress mode, a voltage supply and control block applies a stress enable signal to the interconnected first input terminals, and an increased supply voltage to the voltage supply terminals. During a measurement mode, this block grounds the interconnected first input terminals, and applies a normal supply voltage to the voltage supply terminals. Also included are an analogous NAND-gate based circuit, a circuit combining the NAND- and NOR-aspects, a circuit with a ring oscillator where the inverters may be coupled directly or through inverting paths, and circuits for measuring the bias temperature instability effect in pass gates. | 07-30-2009 |
20090190426 | CIRCUITS, METHODS AND DESIGN STRUCTURES FOR ADAPTIVE REPAIR OF SRAM ARRAYS - The circuit includes a static random access memory array having a plurality of cells, in turn having a plurality of devices; as well as a global sensor having at least one output, coupled to the static random access memory array, and configured to sense at least one of global readability and global write-ability. Also included is a decision-making circuit coupled to the at least one output of the global sensor. The decision-making circuit is configured to determine, from the at least one output of the global sensor, whether adaptation signals are required to correct global readability and/or write-ability. An adaptation signal generation block is also included and is coupled to the decision-making circuit and the array, and configured to supply the adaptation signals to the array, responsive to the decision-making circuit determining that the adaptation signals are required. At least the array and the global sensor, and preferably the decision-making circuit and the adaptation signal generation block as well, are implemented on a single integrated circuit chip. An associated method and design structure(s) are also provided. | 07-30-2009 |
20090251974 | MEMORY CIRCUITS WITH REDUCED LEAKAGE POWER AND DESIGN STRUCTURES FOR SAME - A memory circuit includes a global read bit line, a global read bit line latch, and a plurality of sub-arrays, each of which includes first and second local read bit lines, first and second local write bit lines, and first and second pluralities of memory cells interconnected, respectively, with the first and second local read bit lines and the first and second local write bit lines. The local read bit lines are decoupled from the local write bit lines. A local multiplexing block is interconnected with the first and second local read bit lines and is configured to ground the first and second local read bit lines upon assertion of a SLEEP signal, and to selectively interconnect the local read bit lines to the global read bit line. A global multiplexing block is interconnected with the global read bit line and is configured to maintain the global read bit line in a substantially discharged state upon assertion of the SLEEP signal and to interconnect the global read bit line to the global read bit line latch. Also included are design structures for circuits of the kind described. | 10-08-2009 |
20090310430 | METHODS FOR CHARACTERIZING DEVICE VARIATION IN ELECTRONIC MEMORY CIRCUITS - A circuit includes a comparator circuit configured such that its output toggles from a first digital logical level to a second digital logical level when its first and second inputs transition between a first state wherein the first input has an applied voltage greater than an applied voltage at the second input and a second state wherein the first input has an applied voltage less than an applied voltage at the second input. A plurality of cells each have at least one series-connected pair of field effect transistors interconnected at an output node intermediate the field effect transistors. Decoding logic is configured to select a given one of the cells for measurement, and selectively interconnect the output node of the given one of the cells to the first input of the comparator circuit. Voltage supply circuitry is configured to (i) apply voltages to the gates of the pair of transistors of the given one of the cells selected for measurement, such that the pair of transistors operate in a linear region, and have a variable voltage difference, Δ, between their gate-to-source voltages, and (ii) vary the Δ until the comparator circuit output toggles from the first digital logical level to the second digital logical level. | 12-17-2009 |
20120185817 | Enhanced Static Random Access Memory Stability Using Asymmetric Access Transistors and Design Structure for Same - A memory circuit includes a plurality of bit line structures (each including a true and a complementary bit line), a plurality of word line structures intersecting the plurality of bit line structures to form a plurality of cell locations; and a plurality of cells located at the plurality of cell locations. Each of the cells includes a logical storage element, a first access transistor selectively coupling a given one of the true bit lines to the logical storage element, and a second access transistor selectively coupling a corresponding given one of the complementary bit lines to the logical storage element. One or both of the first and second access transistors are configured with asymmetric current characteristics to enable independent enhancement of READ and WRITE margins. Also included within the 6-T scope are one or more design structures embodied in a machine readable medium, comprising circuits as set forth herein. | 07-19-2012 |
Patent application number | Description | Published |
20120182079 | MONITORING NEGATIVE BIAS TEMPERATURE INSTABILITY (NBTI) AND/OR POSITIVE BIAS TEMPERATURE INSTABILITY (PBTI) - A ring oscillator circuit for measurement of negative bias temperature instability effect and/or positive bias temperature instability effect includes a ring oscillator having first and second rails, and an odd number (at least 3) of repeating circuit structures. Each of the repeating circuit structures in turn includes an input terminal and an output terminal; a first p-type transistor having a gate, a first drain-source terminal coupled to the first rail, and a second drain source terminal selectively coupled to the output terminal; a first n-type transistor having a gate, a first drain-source terminal coupled to the second rail, and a second drain source terminal selectively coupled to the output terminal; and repeating-circuit-structure control circuitry. The ring oscillator circuit also includes a voltage supply and control block. | 07-19-2012 |
20130138403 | USAGE-BASED TEMPORAL DEGRADATION ESTIMATION FOR MEMORY ELEMENTS - Methods and systems for computing threshold voltage degradation of transistors in an array of memory cells are disclosed. In accordance with one method, a process that models an expected usage of the array is selected. In addition, a hardware processor can run the process to populate the array with data over time to simulate the expected usage of the array. The method further includes compiling data that detail different durations at which each of the memory cells in the array stores 1 or at which each of the memory cells in the array stores 0. For each separate grouping of memory cells that share a common duration of the different compiled durations, a threshold voltage degradation is determined for each transistor in the corresponding grouping of cells based on at least one biased temperature instability model. | 05-30-2013 |
20130138407 | USAGE-BASED TEMPORAL DEGRADATION ESTIMATION FOR MEMORY ELEMENTS - Methods and systems for computing threshold voltage degradation of transistors in an array of memory cells are disclosed. In accordance with one method, a process that models an expected usage of the array is selected. In addition, a hardware processor can run the process to populate the array with data over time to simulate the expected usage of the array. The method further includes compiling data that detail different durations at which each of the memory cells in the array stores 1 or at which each of the memory cells in the array stores 0. For each separate grouping of memory cells that share a common duration of the different compiled durations, a threshold voltage degradation is determined for each transistor in the corresponding grouping of cells based on at least one biased temperature instability model. | 05-30-2013 |