Patent application number | Description | Published |
20080273366 | DESIGN STRUCTURE FOR IMPROVED SRAM DEVICE PERFORMANCE THROUGH DOUBLE GATE TOPOLOGY - A design structure embodied in a machine readable medium used in a design process includes a static random access memory (SRAM) device having a pair of cross-coupled, complementary metal oxide semiconductor (CMOS) inverters configured as a storage cell for a bit of data, a first pair of transfer gates configured to couple complementary internal nodes of the storage cell to a corresponding pair of bitlines during a read operation of the device; and a second pair of transfer gates configured to couple the storage cell nodes to the pair of bitlines during a write operation of the device, wherein impedance between the bitlines and the storage cell nodes during the write operation is less than that for the read operation, wherein impedance between the bitlines and the storage cell nodes during the write operation is less than that for the read operation. | 11-06-2008 |
20080273373 | APPARATUS FOR IMPROVED SRAM DEVICE PERFORMANCE THROUGH DOUBLE GATE TOPOLOGY - A static random access memory (SRAM) device a pair of cross-coupled, complementary metal oxide semiconductor (CMOS) inverters configured as a storage cell for a bit of data, a first pair of transfer gates configured to couple complementary internal nodes of the storage cell to a corresponding pair of bitlines during a read operation of the device; and a second pair of transfer gates configured to couple the storage cell nodes to the pair of bitlines during a write operation of the device, wherein impedance between the bitlines and the storage cell nodes during the write operation is less than that for the read operation, wherein impedance between the bitlines and the storage cell nodes during the write operation is less than that for the read operation. | 11-06-2008 |
20090207650 | SYSTEM AND METHOD FOR INTEGRATING DYNAMIC LEAKAGE REDUCTION WITH WRITE-ASSISTED SRAM ARCHITECTURE - 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. | 08-20-2009 |
20090235171 | APPARATUS AND METHOD FOR IMPLEMENTING WRITE ASSIST FOR STATIC RANDOM ACCESS MEMORY ARRAYS - An apparatus for implementing a write assist for a memory array includes a common discharge node configured to provide a discharge path for precharged write data lines and bit lines selected during a write operation of the memory array; negative boost circuitry configured to introduce a voltage lower than a nominal logic low supply voltage onto the common discharge node following the discharge of the common discharge node, write data lines and bit lines; and a clamping device coupled to the common discharge node, the clamping device configured to limit the magnitude of negative voltage applied to common discharge node by the negative boost circuitry so as to prevent activation of non-selected bit switches. | 09-17-2009 |
20100002495 | Column Selectable Self-Biasing Virtual Voltages for SRAM Write Assist - A static random access memory decoder circuit includes a first cell supply line coupled to provide a first column of memory cells a first cell supply voltage and a second cell supply line coupled to provide a first column of memory cells a first cell supply voltage. The decoder circuit further includes a write assist circuit having a first threshold transistor coupled to the first cell supply line and a second threshold transistor coupled to the second cell supply line. In response to a write assist signal, the write assist circuit connects one of the first and second cell supply lines selected by control circuitry to an associated one of the first and second threshold transistors, such that a cell supply voltage of the selected one of the first and second cell supply lines is reduced toward the threshold voltage of the threshold transistor. | 01-07-2010 |
20110280088 | SINGLE SUPPLY SUB VDD BITLINE PRECHARGE SRAM AND METHOD FOR LEVEL SHIFTING - 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. | 11-17-2011 |
20120075919 | Methods and Systems for Adjusting Wordline Up-Level Voltage to Improve Production Yield Relative to SRAM-Cell Stability - 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. | 03-29-2012 |
20130088931 | ASYMMETRIC MEMORY CELLS - An asymmetric memory cell is disclosed. The memory cell includes a refresh control line, a pass gate transistor, and a refresh transistor. The refresh transistor is coupled to the refresh control line, and provides a feedback between the pass gate transistor and a plurality of inverters, when the refresh control line is in a default state. | 04-11-2013 |
20130135944 | DUAL POWER SUPPLY MEMORY ARRAY HAVING A CONTROL CIRCUIT THAT DYANMICALLY SELECTS A LOWER OF TWO SUPPLY VOLTAGES FOR BITLINE PRE-CHARGE OPERATIONS AND AN ASSOCIATED METHOD - Disclosed is a memory array in which the lower of two supply voltages from two power supplies is dynamically selected for bitline pre-charge operations. In the memory array, a voltage comparator compares the first supply voltage on a first power supply rail to a second supply voltage on a second power supply rail and outputs a voltage difference signal. If the voltage difference signal has a first value indicating that the first supply voltage is equal to or less than the second supply voltage, than a control circuit ensures that the complementary bitlines connected to a memory cell are pre-charged to the first supply voltage. If the voltage difference signal has a second value indicating that the first supply voltage is greater than the second supply voltage, then the control circuit ensures that the complementary bitlines are pre-charged to the second supply voltage. Also disclosed is an associated method. | 05-30-2013 |
20130223161 | VDIFF MAX LIMITER IN SRAMS FOR IMPROVED YIELD AND POWER - An integrated circuit structure comprises a static random access memory (SRAM) structure and a logic circuit. A power supply is operatively connected to the SRAM structure, and provides a first voltage to the SRAM structure. A voltage limiter is operatively connected to the power supply. The voltage limiter comprises a switching device operatively connected to the power supply. The switching device receives the first voltage and a second voltage supplied to structures external to the SRAM structure. A resistive element is operatively connected to the switching device. The switching device connects the resistive element to the power supply. The resistive element is selected to enable an output from the switching device to the logic circuit when a difference between the first voltage and the second voltage is greater than a voltage threshold value of the switching device. | 08-29-2013 |
20130275821 | READ ONLY MEMORY (ROM) WITH REDUNDANCY - A read only memory (ROM) with redundancy and methods of use are provided. The ROM with redundancy includes a programmable array coupled to a repair circuit having one or more redundant repairs. The one or more redundant repairs include a word address match logic block, a data I/O address, and a tri-state buffer. The word address match logic block is provided to the tri-state buffer as a control input and the data I/O address is provided to the tri-state buffer as an input. An output of the tri-state buffer of each redundant repair is provided as a first input to one or more logic devices. One or more data outputs of a ROM bit cell array is provided as a second input to a respective one of the one or more logic devices. | 10-17-2013 |
20140351662 | READ ONLY MEMORY (ROM) WITH REDUNDANCY - A read only memory (ROM) with redundancy and methods of use are provided. The ROM with redundancy includes a programmable array coupled to a repair circuit having one or more redundant repairs. The one or more redundant repairs include a word address match logic block, a data I/O address, and a tri-state buffer. The word address match logic block is provided to the tri-state buffer as a control input and the data I/O address is provided to the tri-state buffer as an input. An output of the tri-state buffer of each redundant repair is provided as a first input to one or more logic devices. One or more data outputs of a ROM bit cell array is provided as a second input to a respective one of the one or more logic devices. | 11-27-2014 |