Patent application number | Description | Published |
20090132849 | Method and Computer Program for Selecting Circuit Repairs Using Redundant Elements with Consideration of Aging Effects - A method and computer program for selecting circuit repairs using redundant elements with consideration of aging effects provides a mechanism for raising short-term and long-term performance of memory arrays beyond present levels/yields. Available redundant elements are used as replacements for selected elements in the array. The elements for replacement are selected by BOL (beginning-of-life) testing at a selected operating point that maximizes the end-of-life (EOL) yield distribution as among a set of operating points at which post-repair yield requirements are met at beginning-of-life (BOL). The selected operating point is therefore the “best” operating point to improve yield at EOL for a desired range of operating points or maximize the EOL operating range. For a given BOL repair operating point, the yield at EOL is computed. The operating point having the best yield at EOL is selected and testing is performed at that operating point to select repairs. | 05-21-2009 |
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 |
20090271669 | High-Speed Testing of Integrated Devices - A method for allowing high-speed testability of a memory device having a core with memory cells for storing data, comprising: enabling a data signal having a first logical state or a second logical state from the core to reach an output port of the memory device within an evaluate cycle during a functional operating mode and pass an array built in self test during LBIST mode; enabling the data signal to change from the first logical state to the second logical state during LBIST mode at a time that coincides with the latest possible time the data signal from the core can reach the read output port within the evaluate cycle during the functional operating mode and pass the array built in self test; and executing a logic built-in self test configured to test a logic block located downstream of a transmission path of the memory device. | 10-29-2009 |
20100039876 | Functional Float Mode Screen to Test for Leakage Defects on SRAM Bitlines - A method and system for maintaining Static Random Access Memory (SRAM) functionality while simultaneously screening for leakage paths from bitline to ground during Float Mode operation. The SRAM configuration enables SRAM cell selection for a read or write operation. In response to the SRAM cell selection, a group of pre-charge (PCHG) signals are provided with a high value. When selection is made from a top sub-group of SRAM cells, a corresponding bitline, “BLT_TOP”, takes a value which reflects a state stored in the selected cell. In addition, the bitline corresponding to the bottom sub-group of cells, “BLT_BOT”, takes a high value. If there is a leakage defect, BLT_BOT drops to a low value. With no leakage defect, the data stored in the selected cell is determined based on the result of a logical NAND operation including the respective states indicated by the BLT_TOP and by the BLT_BOT. | 02-18-2010 |
20100195408 | Non-Body Contacted Sense Amplifier with Negligible History Effect - In a method of mitigating hysteresis effect in a sense amplifier circuit, a data value is sensed from a data source with the sense amplifier during a first period. The data value is stored in a latch. The data valued stored in the latch is inverted, thereby generating an inverted data value. The data source is isolated from the sense amplifier and the inverted data value is read with the sense amplifier during a second period immediately following the first period. | 08-05-2010 |
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 |
20120033508 | LEVEL SHIFTER FOR USE WITH MEMORY ARRAYS - In a first aspect, a level shifter circuit for use in a memory array is provided that includes (1) a first voltage domain powered by a first voltage; (2) a second voltage domain powered by a second voltage; (3) level shifter circuitry that converts an input signal from the first voltage domain to the second voltage domain; and (4) isolation circuitry that selectively isolates the first voltage domain from the second voltage domain so as to selectively prevent current flow between the first voltage domain and the second voltage domain. Numerous other aspects are provided. | 02-09-2012 |
20130141986 | IMPLEMENTING COLUMN REDUNDANCY STEERING FOR MEMORIES WITH WORDLINE REPOWERING - A method and circuit for implementing column redundancy steering for memories with wordline repowering, and a design structure on which the subject circuit resides are provided. Each respective data column receives a precharge signal applied to an associated precharge function. An inverting multiplexer is provided in a precharge path after the wordline repowering having inputs coupled to the respective precharge functions before and after the wordline repowering. The inverting multiplexer passes the precharge signal from the precharge function before the wordline repowering or from the precharge function after the wordline repowering. The inverting multiplexer is controlled by the redundancy steering control signal that activates redundancy steering. | 06-06-2013 |
20130201753 | IMPLEMENTING LOW POWER WRITE DISABLED LOCAL EVALUATION FOR SRAM - A method and circuit for implementing low power write disabled local evaluation for Static Random Access Memory (SRAM), and a design structure on which the subject circuit resides are provided. The circuit includes a write disable function to prevent discharge of a global bit line during a write operation. The write disable function disables a NAND gate driving a global pull down device during the write operation preventing the global pull down device from discharging the global bit line. | 08-08-2013 |
20130286717 | IMPLEMENTING SUPPLY AND SOURCE WRITE ASSIST FOR SRAM ARRAYS - A method and circuit for implementing write assist for Static Random Access Memory (SRAM) arrays, and a design structure on which the subject circuit resides are provided. The circuit includes a write driver including a common bit line supply node, and a common bit line source node. The circuit includes voltage boost circuitry that temporarily boosts the common bit line supply node above supply voltage and temporarily boosts the common bit line source node below source voltage through isolation devices for applying the boosted source and supply voltages to a selected SRAM cell during a write operation. Splitting the boost differential between the common bit lines decreases an overall device voltage differential for providing substantially enhanced reliability of the SRAM array. | 10-31-2013 |
20140084980 | MEMORY ARRAY PULSE WIDTH CONTROL - A clock system includes a local clock buffer adapted to receive a variable global clock signal. The local clock buffer produces a first local clock signal from the variable global clock signal. The clock system includes a pulse width logic control circuit in operable communication with the local clock buffer. The pulse width logic control circuit may be adapted to limit the first local clock signal pulse width to be less than the variable global clock signal pulse width during a slow mode. The pulse width logic control circuit may be adapted to expand the first local clock signal pulse width to be greater than the variable global clock signal pulse width during a fast mode. The limited and expanded first local clock signals may signal a local evaluation circuit to address a memory line. | 03-27-2014 |
20140092700 | FINE GRANULARITY POWER GATING - Rows of a memory array are segmented into a predetermined number of word line groups. Each row in a word line group has a word line disposed between parallel power supply lines. Each of the power supply lines in a row of a word line group is shared by an adjacent row in the word line group. A row on a boundary of a word line group has a power supply line shared by a row on a boundary of an adjacent word line group. All power supply lines in a word line group are at a full power voltage in response to one of the rows in the word line group being selected by a word line. Most power supply lines in an adjacent word line group are at a full power voltage. All power supply lines in other word line groups are at a power-gated voltage. | 04-03-2014 |
20140112060 | SRAM GLOBAL PRECHARGE, DISCHARGE, AND SENSE - An SRAM includes a global bit line, an SRAM cell, precharge logic, discharge logic, and sense logic. The SRAM cell stores a first logical value or a second logic value and is coupled to the global bit line. The precharge logic may charge the global bit line to a precharge voltage for a non-read operation and a boosted voltage that is greater than a reference voltage for a read operation. The discharge logic may either maintain the global bit line at the boosted voltage for the first logical value or discharge the global bit line to a discharge voltage that is less than the reference voltage for the second logical value. The sense logic may output the first logical value when the global bit line has the boosted voltage or may output the second logical value when the global bit line has the discharge voltage. | 04-24-2014 |
20140112064 | SRAM GLOBAL PRECHARGE, DISCHARGE, AND SENSE - An SRAM includes a global bit line, an SRAM cell, precharge logic, discharge logic, and sense logic. The SRAM cell stores a first logical value or a second logic value and is coupled to the global bit line. The precharge logic may charge the global bit line to a precharge voltage for a non-read operation and a boosted voltage that is greater than a reference voltage for a read operation. The discharge logic may either maintain the global bit line at the boosted voltage for the first logical value or discharge the global bit line to a discharge voltage that is less than the reference voltage for the second logical value. The sense logic may output the first logical value when the global bit line has the boosted voltage or may output the second logical value when the global bit line has the discharge voltage. | 04-24-2014 |
20140149817 | DIAGNOSTIC TESTING FOR A DOUBLE-PUMPED MEMORY ARRAY - A semiconductor chip and method for diagnostic testing of combinational logic in a logic and array system including Logic Built in Self Test (LBIST) diagnostics are provided. The semiconductor chip includes a logic and array system, an LBIST system, a clocking module, and an addressing module. The method for diagnostic testing includes providing an initialization pattern to an array in the logic and array system, applying a diagnostic control setup, and running the diagnostic test. The diagnostic control setup includes firing a clock every diagnostic test clock cycle and selecting an address from a subset of an address space. | 05-29-2014 |
20140149818 | DIAGNOSTIC TESTING FOR A DOUBLE-PUMPED MEMORY ARRAY - A semiconductor chip and method for diagnostic testing of combinational logic in a logic and array system including Logic Built in Self Test (LBIST) diagnostics are provided. The semiconductor chip includes a logic and array system, an LBIST system, a clocking module, and an addressing module. The method for diagnostic testing includes providing an initialization pattern to an array in the logic and array system, applying a diagnostic control setup, and running the diagnostic test. The diagnostic control setup includes firing a clock every diagnostic test clock cycle and selecting an address from a subset of an address space. | 05-29-2014 |