Flip-flop (electrical) Patents (Class 365/154)
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SYSTEMS AND METHODS FOR REDUCING MEMORY ARRAY LEAKAGE IN HIGH CAPACITY MEMORIES BY SELECTIVE BIASING
Publication number: 20110063893Abstract: A source-biasing mechanism for leakage reduction in SRAM in which SRAM cells are arranged into a plurality of sectors. In standby mode, the SRAM cells in a sector in the plurality of sectors are deselected and a source-biasing potential is provided to the SRAM cells of the plurality sectors. In working mode, the source-biasing potential provided to the SRAM cells of a selected sector in the plurality of sectors is deactivated and the SRAM cells in a physical row within the selected sector are read while the remaining SRAM cells in the unselected sectors continue to be source-biased. The source-biasing potential provided to the SRAM cells that are in standby mode can be set to different voltages based on the logical state of control signals.Type: ApplicationFiled: September 14, 2009Publication date: March 17, 2011Inventors: Niranjan Behera, Deepak Sabharwal, Yong Zhang -
Patent number: 7907438Abstract: In a semiconductor integrated circuit having a register file of a multiport configuration, a first holding circuit 20A is dedicated to a first functional block having one first write port section 21AW and two first read port sections 21AR1 and 21AR2. A second holding circuit 30B is dedicated to a second functional block having one second write port section 31AW and one second read port section 31BR. When it is necessary to read data held in the first holding circuit 20A from the second read port section 31BR, for example, a data interchange operation is performed as follows. After the data of the second holding circuit 30B is latched in a latch circuit 40, the data of the first holding circuit 20A is transferred to the second holding circuit 30B, and then the data of the second holding circuit 30B latched in the latch circuit 40 is transferred to the first holding circuit 20A. Thus, the area necessary to provide a register file is significantly reduced.Type: GrantFiled: January 14, 2010Date of Patent: March 15, 2011Assignee: Panasonic CorporationInventor: Masaya Sumita
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Structures and methods of preventing an unintentional state change in a data storage node of a latch
Patent number: 7907461Abstract: A method of preventing an unintentional state change in a data storage node of a latch is disclosed. The method comprises receiving a reference input signal; generating a delayed input signal based upon the reference clock signal; maintaining a state of a first data storage node of a plurality of data storage nodes by latching data at the first node using the reference input signal; and maintaining a state of a second data storage node of the plurality of data storage nodes by latching data at the second data storage node using the delayed input signal. A circuit for preventing an unintentional state change in a data storage node of a latch is also disclosed.Type: GrantFiled: March 3, 2008Date of Patent: March 15, 2011Assignee: Xilinx, Inc.Inventors: Chi Minh Nguyen, Martin L. Voogel -
Patent number: 7907457Abstract: A memory and a voltage monitoring device thereof are provided. the voltage monitoring device of the memory includes a system voltage detector, a charge pump circuit and a data output unit. The system voltage detector is coupled to the charge pump circuit and the data output unit for detecting a system voltage and thereby producing control signals. The charge pump circuit can produce a word line voltage according to the above-mentioned control signals. The data output unit decides outputting the above-mentioned control signals or the output data of the memory according to a special command, wherein the control signals correspond to the word line voltages. Therefore, the control signals and the word line voltages may be easily monitored.Type: GrantFiled: March 12, 2008Date of Patent: March 15, 2011Assignee: Winbond Electronics Corp.Inventor: Po-Chang Wu
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Patent number: 7907456Abstract: An integrated circuit (IC) includes at least one memory array having a plurality of memory cells arranged in a plurality of rows and columns, the array also having a plurality of word lines for accessing rows of cells and a plurality bit lines for accessing columns of cells. A voltage differential generating circuit is operable to provide a differential wordline voltage (VWL) relative to an array supply voltage, wherein the differential is a function of the array supply voltage.Type: GrantFiled: October 31, 2007Date of Patent: March 15, 2011Assignee: Texas Instruments IncorporatedInventors: Theodore W. Houston, Andrew Marshall
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Patent number: 7903451Abstract: According to one embodiment, a storage apparatus includes: a first inverter; a second inverter; a first storage element having a first state and a second state; and a second storage element having a third state and a fourth state, wherein the first storage element is brought into the first state when a current flows from the first storage element to the first storage element and is brought into the second state when the current flows from the first storage element to the first storage element, wherein the second storage element is brought into the fourth state when a current flows from the second storage element to the second storage element and is brought into the third state when the current flows from the second storage element to the second storage element.Type: GrantFiled: March 16, 2009Date of Patent: March 8, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Yutaka Yamada, Tatsunori Kanai, Masaya Tarui, Keiko Abe
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Patent number: 7903450Abstract: Asymmetrical SRAM cells are improved by providing one or more of improved read stability and improved write performance and margin. A first inverter and a second inverter are cross-coupled and configured for selective coupling to true and complementary bit lines under control of read and write word lines. The first inverter is formed by a first, n-type, FET (NFET) and a second, p-type, FET (PFET). Process and/or technology approaches can be employed to adjust the relative strength of the FETS to obtain, for example, read margin, write margin, and/or write performance improvements.Type: GrantFiled: March 3, 2008Date of Patent: March 8, 2011Assignee: International Business Machines CorporationInventors: Ching-Te Chuang, Jae-Joon Kim, Keunwoo Kim
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Patent number: 7903490Abstract: The present invention provides a semiconductor memory device in which the number of write amplifiers is decreased by increasing the number of bit line pairs connected to one pair of common write data lines. Further, by decreasing the number of bit line pairs connected to one pair of common read data lines, parasitic capacitance connected to the pair of common read data lines is reduced and, accordingly, time in which the potential difference between the pair of common read data lines increases is shortened. Thus, while preventing enlargement of the chip layout area, read time can be shortened.Type: GrantFiled: September 16, 2008Date of Patent: March 8, 2011Assignee: Renesas Electronics CorporationInventors: Hajime Sato, Masao Shinozaki
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Publication number: 20110051539Abstract: A parametric test circuit is disclosed (FIG. 8B). The test circuit includes a latch circuit having true and complementary terminals. A first access transistor (206) has a current path connected between the true terminal and a first access terminal (214) and has a first control terminal. A second access transistor (208) has a current path connected between the complementary terminal and a second access terminal (216) and has a second control terminal connected to the first control terminal. A multiplex circuit (804) is arranged to apply a first voltage (VDD1) to the first power supply terminal in response to a first state of a select signal (SEL) and to apply a second voltage (VDD2) to the first power supply terminal in response to a second state of a select signal.Type: ApplicationFiled: September 1, 2009Publication date: March 3, 2011Inventors: Xiaowei Deng, Wah Kit Loh
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Publication number: 20110051501Abstract: The present invention relates to a memory circuit and a method of controlling data retention in the memory circuit, wherein a supply signal is selectively switched to a respective one of at least two virtual supply lines (24) each shared by a respective one of a plurality of groups (30-1 to 30-n) of memory cells (C0,0 to Cy,z). The selective switching is controlled based on a global activity control signal (A), used for setting the memory circuit either into a standby state or into an active state, and a local data retention indication signal (DR1 to DRn) allocated to a dedicated group of memory cells. Thereby, the data retention part of the memory circuit can be adapted to the application and its state, and standby mode leakaged power is only dissipated in those memory cells for which data retentions actually required.Type: ApplicationFiled: August 30, 2010Publication date: March 3, 2011Inventor: Cornelis Hermanus Van Berkel
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Publication number: 20110051540Abstract: A parametric test circuit is disclosed (FIG. 6). The test circuit includes a latch circuit having true and complementary terminals. A first access transistor (206) has a current path connected between the true terminal and a first access terminal (214) and has a first control terminal. A second access transistor (208) has a current path connected between the complementary terminal and a second access terminal (216) and has a second control terminal connected to the first control terminal. A first pass gate (604) has a current path connected between the first access terminal (214) and a third access terminal (XBLT) and has a third control terminal. A second pass gate (606) has a current path connected between the second access terminal (216) and a fourth access terminal (XBLB) and has a fourth control terminal connected to the third control terminal.Type: ApplicationFiled: September 1, 2009Publication date: March 3, 2011Inventors: Xiaowei Deng, Wah Kit Loh
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Patent number: 7898843Abstract: Methods and apparatus are provided for read/write control and bit selection with false read suppression in an SRAM. According to one aspect of the invention, a bit select circuit is provided for an SRAM. The disclosed bit select circuit comprises one or more transistors controlled by a write control gate signal to prevent data from being read from one or more data cells during a write operation. The transistors can comprise, for example, a pair of gated transistors controlled by the write control gate signal. The write control gate signal prevents data from being read from one or more data cells while the write control gate signal is in a predefined state.Type: GrantFiled: June 17, 2008Date of Patent: March 1, 2011Assignee: International Business Machines CorporationInventor: Rajiv V. Joshi
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Patent number: 7898896Abstract: The present invention provides a technique capable of simplifying a layout structure of a semiconductor device having a semiconductor memory section in which an input port and an output port are separated from each other, and which includes a bypass function. In a semiconductor memory device to be used as a semiconductor memory section of the semiconductor device, in a bypass mode, an output buffer outputs input data transmitted through a bypass line, extending from an input buffer circuit to the output buffer circuit, to an output port. In the layout structure of the semiconductor memory device, in plan view, a memory cell array is arranged between the input buffer circuit and the output buffer circuit, and a bypass line is arranged through between the memory cell arrays.Type: GrantFiled: March 25, 2009Date of Patent: March 1, 2011Assignee: Renesas Electronics CorporationInventor: Atsushi Miyanishi
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Patent number: 7898894Abstract: The present invention provides an improved SRAM cell. Specifically, the present invention provides an SRAM cell having one or more sets of stacked transistors for isolating the cell during a read operation. Depending on the embodiment, the SRAM cell of the present invention can have eight or ten transistors. Regardless, the SRAM cell of the present invention typically includes separate/decoupled write word and read word lines, a pair of cross-coupled inverters, and a complimentary pair of pass transistors that are coupled to the write word line. Each set of stacked transistors implemented within the SRAM cell has a transistor that is coupled to a bit line as well as the read word line.Type: GrantFiled: April 12, 2006Date of Patent: March 1, 2011Assignee: International Business Machines CorporationInventors: Leland Chang, Rajiv V. Joshi, Stephen V. Kosonocky
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Patent number: 7898887Abstract: A sense amplifier includes a first sensing element and a second sensing element redundant to the first sensing element. The sense amplifier further comprises a switch circuit configured to switch between the first and second sensing elements when an offset of the sense amplifier is greater than a prescribed amount.Type: GrantFiled: August 29, 2007Date of Patent: March 1, 2011Assignee: Agere Systems Inc.Inventors: Dennis E. Dudeck, Donald Albert Evans, Hai Quang Pham, Wayne E. Werner, Ronald James Wozniak
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Patent number: 7899434Abstract: A communication device includes a voice data and RF integrated circuit (IC) that includes a memory module that stores a least one application as a plurality of operational instructions, the at least one application having a plurality of power modes that each correspond to one of a plurality of use characteristics. A processing module executes the plurality of operational instructions and determines a selected one of the plurality of power modes based on current use characteristics of the at least one application, and the generates a power mode signal based on the selected one of the plurality of power modes. An off-chip power management circuit receives the power mode signal and that generates a plurality of power supply signals to the voice data and RF IC based on the power mode signal.Type: GrantFiled: December 15, 2006Date of Patent: March 1, 2011Assignee: Broadcom CorporationInventors: Yossi Cohen, Nelson R. Sollenberger, Vafa James Rakshani, Ahmadreza (Reza) Rofougaran, Maryam Rofougaran, Claude G. Hayek, Frederic Christian Marc Hayem
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Patent number: 7898842Abstract: A memory cell for storing a binary state, the memory cell being adapted for storing a binary state based on a write indication and a binary write masking value and for storing a complementary binary state based on the write indication and a complementary binary write masking value.Type: GrantFiled: April 21, 2008Date of Patent: March 1, 2011Assignee: Infineon Technologies AGInventor: Thomas Kuenemund
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Publication number: 20110044095Abstract: The present invention provides a semiconductor memory device in which the number of write amplifiers is decreased by increasing the number of bit line pairs connected to one pair of common write data lines. Further, by decreasing the number of bit line pairs connected to one pair of common read data lines, parasitic capacitance connected to the pair of common read data lines is reduced and, accordingly, time in which the potential difference between the pair of common read data lines increases is shortened. Thus, while preventing enlargement of the chip layout area, read time can be shortened.Type: ApplicationFiled: October 26, 2010Publication date: February 24, 2011Inventors: Hajime Sato, Masao Shinozaki
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Publication number: 20110044094Abstract: An integrated circuit including a ram array with SRAM cells containing a write port with a write word line and two read buffers with read word lines. The write port includes passgate transistors connected to each data node of the SRAM cell. A process of operating the integrated circuit in which source nodes of read buffer driver transistors are biased during a read operation. A process of operating the integrated circuit in which source nodes of read buffer driver transistors are floated during a read operation. A process of operating the integrated circuit in which the write port and the read ports share data lines and the source nodes of read buffer driver transistors are floated during a write operation.Type: ApplicationFiled: August 24, 2009Publication date: February 24, 2011Applicant: Texas Instruments IncorporatedInventor: Theodore W. Houston
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Patent number: 7894226Abstract: A scheme for ultra-low power content addressable memory based on a ripple search is disclosed. In one embodiment, a system for content addressable memory (CAM), includes a storage unit for storing a portion of content data, and a match module for comparing the portion of the content data with a respective portion of search data received by the match module. The match module includes a first static logic gate associated with a first half of the storage unit storing a sub-portion of the portion of the content data, and a second static logic gate associated with a second half of the storage unit. The first static logic gate forwards a signal for disabling the second static logic gate if the sub-portion of the portion of the content data does not match with a respective sub-portion of the portion of the search data.Type: GrantFiled: May 21, 2008Date of Patent: February 22, 2011Assignee: Texas Instruments IncorporatedInventors: Shahid Ali, Sharad Gupta, Sunil Kumar Misra
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Patent number: 7894234Abstract: A process of polarizing a programmable data storage component of an integrated circuit by polarizing the ferroelectric capacitors in the same orientation and then removing power from the integrated circuit. A process polarizing a programmable data storage component of an integrated circuit by polarizing the ferroelectric capacitors in the same orientation, then removing power from the integrated circuit. A process of polarizing a programmable data storage component of an integrated circuit by polarizing corresponding ferroelectric capacitors in same orientations, then removing power from the integrated circuit. An integrated circuit containing a programmable data storage component and a ferroelectric capacitor polarization circuit that is configured to polarize a first data ferroelectric capacitor and a second data ferroelectric capacitor in desired polarization configurations by applying biases to a first state node, a second state node, a first plate node, and a second plate node.Type: GrantFiled: July 14, 2009Date of Patent: February 22, 2011Assignee: Texas Instruments IncorporatedInventors: John A. Rodriguez, Scott R. Summerfelt
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Patent number: 7894242Abstract: Device for storing a binary state defined by a first binary value and a second binary value complementary thereto, the device capable of being queried by a query signal so as to output, in dependence on a binary masking state, the first binary value at a first output and the second binary value at a second output or vice versa.Type: GrantFiled: February 27, 2008Date of Patent: February 22, 2011Assignee: Infineon Technologies AGInventors: Thomas Kuenemund, Andreas Wenzel
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Patent number: 7894280Abstract: An integrated circuit includes a memory array having a plurality of SRAM memory cells arranged in a plurality of rows and columns, the array also having a plurality of word lines for accessing rows of cells and a plurality bit lines for accessing columns of cells. The plurality of memory cells include a plurality of asymmetric cells, each of the asymmetric cells configured with a strong side including a first inverter having a strong side latch node, and a strong side pass transistor coupled to the strong side latch node, and a weak side including a second inverter cross-coupled with the first inverter having a weak side latch node and a weak side pass transistor coupled to the weak side latch node. Separate ones of the plurality of word lines are coupled to a gate of the strong side pass transistor and a gate of the weak side pass transistor.Type: GrantFiled: October 31, 2007Date of Patent: February 22, 2011Assignee: Texas Instruments IncorporatedInventor: Theodore W. Houston
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Patent number: 7889576Abstract: This invention provides static random access memory (SRAM). The SRAM has a plurality of memory cells arranged in row and column directions. The plurality of memory cells each have a latch circuit in which input and output terminals of a pair of inverters are cross-connected and which maintains complementary levels at a pair of storage nodes, and a pair of write transistors provided between the pair of storage nodes and a prescribed power supply voltage. Further, the gate potentials of the pair of write transistors are respectively controlled according to a row address, a column address, and write data.Type: GrantFiled: March 26, 2009Date of Patent: February 15, 2011Assignee: Fujitsu LimitedInventor: Hirotoshi Sasaki
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Patent number: 7889582Abstract: A memory device is provided for performing writing operations on memory cells while maintaining a stability thereof. A memory array is provided including a plurality of memory cells. Additionally, segmented write bitlines are provided for performing writing operations on the memory cells while maintaining a stability thereof.Type: GrantFiled: March 12, 2008Date of Patent: February 15, 2011Assignee: NetLogic Microsystems, Inc.Inventor: Steven Butler
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Patent number: 7889540Abstract: A semiconductor device has a first inverter including a drive transistor and a load transistor; a second inverter including a drive transistor and a load transistor, a transmission transistor provided between the output terminal of the first inverter and one line of a bit line pair, a transmission transistor provided between the output terminal of the second inverter and the other line of the bit line pair; and an isolation transistor for isolating the drive transistor and the transmission transistor. The transmission transistor, the transmission transistor, the drive transistor, and the isolation transistor are formed in a continuous active region and the isolation transistor is provided between the drive transistor and the transmission transistor.Type: GrantFiled: September 5, 2008Date of Patent: February 15, 2011Assignee: Renesas Electronics CorporationInventor: Shinobu Asayama
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Patent number: 7889541Abstract: A SRAM cell structure includes a first N type switch, a second N type switch, a first storage node, and a second storage node. The first N type switch has a control terminal connected to a word line and a first terminal connected to a bit line. The second N type switch has a control terminal connected to the word line and a first terminal connected to an inverted bit line. The first storage node has a first terminal connected to a second terminal of the first N type switch. The second storage node has a first terminal connected to a second terminal of the second N type switch.Type: GrantFiled: April 10, 2009Date of Patent: February 15, 2011Assignee: Faraday Technology Corp.Inventors: Wei-Chiang Shih, Chen-Hao Po, Kwo-Jen Liu
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Publication number: 20110032750Abstract: A driver power supply circuit stepping down a power supply voltage is arranged at a power supply node of a word line driver. The driver power supply circuit includes a non-silicide resistance element of N+ doped polycrystalline silicon, and a pull-down circuit lowering a voltage level of the driver power supply node. The pull-down circuit includes a pull-down transistor having the same threshold voltage characteristics as a memory cell transistor pulling down a voltage level of the driver power supply node, and a gate control circuit adjusting at least a gate voltage of the pull-down transistor. The gate control circuit corrects the gate potential of the pull-down transistor in a manner linked to variations in threshold voltage of the memory cell transistor.Type: ApplicationFiled: October 21, 2010Publication date: February 10, 2011Applicant: Renesas Electronics CorporationInventors: Makoto Yabuuchi, Koji Nii
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Patent number: 7885093Abstract: A method testing an SRAM having a plurality of memory cells is disclosed. In a first step, a bit value is written into a cell under test (CUT). Subsequently, the first and second enabling transistors are disabled and the bit lines are discharged to a low potential. Next, the word line (WL) coupled to the memory cell under test is activated for a predetermined period. During a first part of this period, one of the bit lines (BLB) is kept at the low potential to force the associated pull up transistor in the CUT into a conductive state, after which this bit line (BLB) is charged to a high potential. Upon completion of this period, the bit value of the first cell is determined. The method facilitates the detection of weak or faulty SRAM cells without requiring the inclusion of dedicated hardware for this purpose.Type: GrantFiled: August 21, 2007Date of Patent: February 8, 2011Assignee: NXP B.V.Inventors: Paul Wielage, Mohamed Azimane
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Patent number: 7885092Abstract: A semiconductor storage device includes: a bit line; a first word line; a second word line; a first inverter in which one terminal of a first load transistor is connected to a first driver transistor and their junction point forms a first node; a second inverter in which one terminal of a second load transistor is connected to a second driver transistor and their junction point forms a second node; a first write transistor one terminal of which is connected to the first load transistor and the other terminal of which is connected to a power supply voltage; a second write transistor one terminal of which is connected to the first driver transistor and the other terminal is connected to a reference potential; and an access transistor one terminal of which is connected to the first node and the other terminal of which is connected to the bit line.Type: GrantFiled: February 20, 2009Date of Patent: February 8, 2011Assignee: Sony CorporationInventor: Masaya Uematsu
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Publication number: 20110026312Abstract: A semiconductor device includes a memory cell which includes a first inverter and a second inverter, the first inverter includes a first drive transistor and a first load transistor, the second inverter includes a second drive transistor and a second load transistor, and an input terminal and an output terminal thereof, respectively, connected to an input terminal and an output terminal of the first inverter, a first transmission transistor provided between the output terminal of the first inverter and a line of a first bit line pair, a second transmission transistor provided between the output terminal of the second inverter and another line of the first bit line pair, a third transmission transistor provided between the output terminal of the first inverter and a line of a second bit line pair, a fourth transmission transistor provided between the output terminal of the second inverter and another line of the second bit line pair, and a first isolation transistor which isolates the second drive transistor aType: ApplicationFiled: October 6, 2010Publication date: February 3, 2011Applicant: NEC ELECTRONICS CORPORATIONInventor: Shinobu Asayama
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Publication number: 20110026311Abstract: A one read/two write SRAM circuit of which memory cell size is small, and high-speed operation is possible. The SRAM circuit includes first and second flip-flop circuits which are connected in parallel to a common write word line; a first write control circuit which is connected to said first flip-flop circuit, is conducted by a write control signal supplied to said write word line, and supplies a first write signal to said first flip-flop circuit; and a second write control circuit which is connected to said second flip-flop circuit, is conducted by a write control signal supplied to said write word line, and supplies a second write signal to said second flip-flop circuit.Type: ApplicationFiled: October 1, 2010Publication date: February 3, 2011Applicant: FUJITSU LIMITEDInventor: Katsunao Kanari
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Publication number: 20110026315Abstract: A circuit and method are provided in which a six-transistor (6-T) SRAM memory cell is hardened to single-event upsets by adding isolation-field effect transistors (“iso-fets”) connected between the reference voltage Vdd and the field-effect transistors (“fets”) respectively corresponding to first and second inverters of the memory cell. According to certain embodiments, the control gates of first and second P-iso-fets are respectively tied to the control gates of first and second pull-up P-fets. According to certain embodiments, first and second N-iso-fets are connected between the output nodes of the memory cell and the pull-down N-fets respectively corresponding to the first and second inverters. The control gates of the first and second N-iso-fets are respectively tied to the control gates of the first and second pull-down N-fets. Again according to certain embodiments, one or more of the iso-fets are physically removed from the proximity of other transistors which comprise the memory cell.Type: ApplicationFiled: October 7, 2010Publication date: February 3, 2011Applicant: BAE Systems Information and Electronic Systems Integration Inc.Inventors: Reed K. Lawrence, Nadim F. Haddad
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Publication number: 20110026313Abstract: A loadless static random access memory cell is provided. The memory cell includes four transistors. The first transistor has a gate terminal corresponding to a word line of the memory cell, a source/drain terminal corresponding to a first bit line of the memory cell, and a drain/source terminal corresponding to a first storage node of the memory cell. The second transistor has a gate terminal corresponding to the word line, a source/drain terminal corresponding to a second bit line of the memory cell, and a drain/source terminal corresponding to a second storage node of the memory cell. The third transistor has a gate terminal coupled to the second storage node, a drain terminal coupled to the first storage node, a source terminal corresponding to a reference voltage, and a body terminal directly connected to the third gate terminal.Type: ApplicationFiled: July 29, 2009Publication date: February 3, 2011Applicant: GLOBALFOUNDRIES Inc.Inventor: Hyunjin Cho
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Publication number: 20110026309Abstract: A write boost circuit provides an automatic mode control for boost with different modalities with respect to the external supply voltage and also with respect to the extent of boost required at different process corners. The write boost circuit also takes care of the minimum boost provided to process corners with good writability where less boost is required. The boost is realized in terms of ground raising in the particular context and in general applicable to all other methods.Type: ApplicationFiled: September 30, 2009Publication date: February 3, 2011Applicant: STMicroelectronics Pvt. Ltd.Inventors: Ashish KUMAR, Naveen Batra
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Publication number: 20110026310Abstract: A semiconductor memory, such as an SRAM, is described that accommodates smaller read/write accesses in one mode of operation and larger read/write accesses in a second mode of operation, wherein power is conserved during the smaller accesses. Methods of using such a semiconductor memory are also described.Type: ApplicationFiled: October 11, 2010Publication date: February 3, 2011Applicant: BROADCOM CORPORATIONInventor: Stephen Mueller
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Publication number: 20110026289Abstract: A multi-port SRAM cell includes cross-coupled inverters each including a pull-up transistor and at least a pair of pull down transistors. The SRAM cell includes first and second access ports coupled to first and second word line conductors, each access port including a first pass gate transistor coupled to the data storage node and a second pass gate transistor coupled to the data bar storage node, each pass gate transistor being coupled to a respective bit line conductor, wherein the pull down transistors of the first inverter are formed in a first active region, the pull down transistors of the second inverter are formed in a second active region, the pass gate transistors coupled to the data storage node are formed in a third active region and the pass gate transistors coupled to the data bar storage node are formed in a fourth active region.Type: ApplicationFiled: January 4, 2010Publication date: February 3, 2011Applicant: TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD.Inventor: Jhon Jhy LIAW
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Publication number: 20110026308Abstract: A multi-port SRAM cell includes cross-coupled inverters each including a pull-up transistor and at least a pair of pull down transistors. The SRAM cell includes first and second access ports coupled to first and second word line conductors, each access port including a first pass gate transistor coupled to the data storage node and a second pass gate transistor coupled to the data bar storage node, each pass gate transistor being coupled to a respective bit line conductor, wherein the pull down transistors of the first inverter are formed in a first active region, the pull down transistors of the second inverter are formed in a second active region, the pass gate transistors coupled to the data storage node are formed in a third active region and the pass gate transistors coupled to the data bar storage node are formed in a fourth active region.Type: ApplicationFiled: July 31, 2009Publication date: February 3, 2011Applicant: TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD.Inventor: Jhon Jhy Liaw
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Publication number: 20110019463Abstract: A static random access memory device capable of preventing stability issues during a write operation is provided, in which a memory cell is coupled to a read word line, a write word line, a read bit line, a write bit line and a complementary write bit line, and a multiplexing unit is coupled to the read bit line, the write bit line and the complementary write bit line. The multiplexing unit applies first and second logic voltages representing a logic state stored in the memory cell to the write bit line and the complementary write bit line, respectively, when the memory cell is not selected to be written by an input signal from a data driver and the read word line is activated, in which the first and second logic voltages are opposite to each other.Type: ApplicationFiled: October 5, 2010Publication date: January 27, 2011Applicant: MEDIATEK INC.Inventor: Chia-Wei Wang
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Patent number: 7876601Abstract: The logic cells (HLEs) of a structured application-specific integrated circuit (structured ASIC) can be used to provide memory blocks of various sizes. Any one or more of several techniques may be employed to facilitate doing this for various user designs that may have different requirements (e.g., in terms of size) for such memory blocks. For example, pre-designed macros of memory blocks may be provided and then combined as needed to provide memory blocks of various sizes. Placement constraints may be observed for certain portions of the memory circuitry (e.g., the memory core), while other portions (e.g., address predecoder circuitry, write and read data registers, etc.) may be located relatively freely.Type: GrantFiled: June 14, 2010Date of Patent: January 25, 2011Assignee: Altera CorporationInventor: David Lewis
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Patent number: 7876602Abstract: A circuit and method are provided in which a six-transistor (6-T) SRAM memory cell is hardened to single-event upsets by adding isolation-field effect transistors (“iso-fets”) connected between the reference voltage Vdd and the field-effect transistors (“fets”) respectively corresponding to first and second inverters of the memory cell. According to certain embodiments, the control gates of first and second P-iso-fets are respectively tied to the control gates of first and second pull-up P-fets. According to certain embodiments, first and second N-iso-fets are connected between the output nodes of the memory cell and the pull-down N-fets respectively corresponding to the first and second inverters. The control gates of the first and second N-iso-fets are respectively tied to the control gates of the first and second pull-down N-fets. Again according to certain embodiments, one or more of the iso-fets are physically removed from the proximity of other transistors which comprise the memory cell.Type: GrantFiled: June 18, 2008Date of Patent: January 25, 2011Assignee: BAE Systems Information and Electronic Systems Integration Inc.Inventors: Reed K. Lawrence, Nadim F. Haddad
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Patent number: 7876600Abstract: An SRAM and a forming method and a controlling method thereof are provided. The above-mentioned SRAM includes a tracking column, a normal column, a cell voltage control circuit and a cell voltage pull-down circuit. Each of the tracking column and the normal column includes a plurality of memory cells. The cell voltage control circuit is coupled to the tracking column and the normal column for connecting an operation voltage to the two columns before a write operation of the SRAM starts and for disconnecting the operation voltage from the two columns after the write operation starts. The cell voltage pull-down circuit is coupled to the two columns for pulling down the cell voltages of the two columns after the write operation starts and for ceasing pulling down the cell voltage of the normal column when the cell voltage of the tracking column drops down to a predetermined voltage.Type: GrantFiled: November 17, 2008Date of Patent: January 25, 2011Assignee: Aicestar Technology (SuZhou) CorporationInventors: Jin-Feng Zhang, Jian-Bin Zheng, Zhao-Yong Zhang, Qi-Shuang Yao
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Patent number: 7872894Abstract: A memory cell is protected against current or voltage spikes. The cell includes a group of redundant data storage nodes for the storage of information in at least one pair of complementary nodes. The cell further includes circuitry for restoring information to its initial state following a current or voltage spike which modifies the information in one of the nodes of the pair using the information stored in the other node. The data storage nodes of each pair in the cell are implanted on opposite sides of an opposite conductivity type well from one another within a region of a substrate defining the boundaries of the memory cell.Type: GrantFiled: April 10, 2009Date of Patent: January 18, 2011Assignee: STMicroelectronics S.A.Inventors: Philippe Roche, Francois Jacquet
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Patent number: 7872938Abstract: A Static Random Access Memory (SRAM) cell storage configuration is described, having an improved robustness to radiation induced soft errors. The SRAM cell storage configuration comprises the following elements. First and second storage nodes are configured to store complementary voltages. Drive transistors are configured to selectively couple one of the first and second storage nodes to ground. Load transistors are configured to selectively couple the other one of the first and second storage nodes to a power supply. At least one stabilizer transistor is configured to provide a corresponding redundant storage node and limit feedback between the first and second storage nodes, the redundant storage node being capable of restoring the first or second storage nodes in case of a soft error.Type: GrantFiled: August 28, 2009Date of Patent: January 18, 2011Assignee: CertiChip Inc.Inventors: Manoj Sachdev, Shah M Jahinuzzaman
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Patent number: 7872935Abstract: Static random access memory (SRAM) cells and methods of operation are provided which may be used to provide improved writeability and stability to support low voltage operation of memory devices. For example, in one implementation, by temporarily interrupting the connection between portions of an SRAM cell and a power source such as a reference voltage or current source, the writeability of SRAM cells can be improved. Additional read port implementations are also provided to facilitate low voltage operation. In another implementation, a power switch circuit responsive to a word line and logic signals may be used to provide such interruptions.Type: GrantFiled: June 26, 2009Date of Patent: January 18, 2011Assignee: Oracle America, Inc.Inventor: Ajay Bhatia
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Patent number: 7872903Abstract: Memory elements are provided that exhibit immunity to soft error upset events when subjected to high-energy atomic particle strikes. The memory elements may each have ten transistors including two address transistors and four transistor pairs that are interconnected to form a bistable element. Clear lines such as true and complement clear lines may be routed to positive power supply terminals and ground power supply terminals associated with certain transistor pairs. During clear operations, some or all of the transistor pairs can be selectively depowered using the clear lines. This facilitates clear operations in which logic zero values are driven through the address transistors and reduces cross-bar current surges.Type: GrantFiled: March 19, 2009Date of Patent: January 18, 2011Assignee: Altera CorporationInventor: Bruce B. Pedersen
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Patent number: 7872930Abstract: A supply voltage is set for a memory device at a first supply voltage level. Test data is written to the memory device at the first supply voltage level in response to setting the supply voltage. The supply voltage is decreased for the memory device to a second supply voltage level below the first supply voltage level in response to writing the test data. The test data is read from the memory device at the second supply voltage level in response to decreasing the supply voltage. The supply voltage is increased for the memory device to a third supply voltage level above the second supply voltage level in response to reading the test data. The test data is read from the memory device at the third supply voltage level in response to increasing the supply voltage.Type: GrantFiled: May 15, 2008Date of Patent: January 18, 2011Assignee: QUALCOMM, IncorporatedInventors: Nan Chen, Sian-Yee Sean Lee, Seong-Ook Jung, Zhongze Wang
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Publication number: 20110007556Abstract: A SRAM architecture comprises a read/write control signal, a read/write control transistor block, an equalize transistor block, a 6-T SRAM cell, a sense amplifier block, a column selection transistor block and a write driver. The 6-T SRAM cell can store and write data. The sense amplifier block is used to read out the data stored in the 6-T SRAM cell correctly when the SRAM architecture performs a read operation and makes bit lines BL (bit line) and BLB( bitline) produce a minimum voltage difference. The column selection transistor block is used to select a column that the data is written in and read out stored in. The write driver is used to perform a write operation to the 6-T SRAM cell of the column. The SRAM architecture can effectively increase the read SNM and dramatically reduce the power consumption.Type: ApplicationFiled: July 8, 2009Publication date: January 13, 2011Inventors: Cihun-Siyong Gong, Ci-Tong Hong, Muh-Tian Shiue, Kai-Wen Yao
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Publication number: 20110007557Abstract: An SRAM cell includes one pair of drive transistors, one pair of load transistors, one pair of write access transistors, one pair of read drive transistors, and one pair of access transistors. A voltage source potential is supplied to drains of the read drive transistors.Type: ApplicationFiled: March 8, 2010Publication date: January 13, 2011Applicant: Kabushiki Kaisha ToshibaInventors: Yusuke NIKI, Keiichi KUSHIDA
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Patent number: RE42145Abstract: An SRAM bit cell with cross-coupled inverters has separate write and read buses. Writing is performed through an NMOS pass transistor. Reading is performed through a PMOS transistor. Because the NMOS transistor does not pass a logic 1 as easily as logic 0, assistance is needed to speed up writing of a logic 1 value relative to the time required to write a logic 0 value. An NMOS pre-charge transistor is coupled between the read bus and ground potential; and, a read is performed simultaneously with a write. This conditions the cell by weakening one of the inverters, such that they cross-couple more quickly when a logic 1 value is written into the cell. Alternatively, a single-ended read/write bus can be coupled to the NMOS pass transistor with write-assistance provided by grounding the PMOS pass transistor.Type: GrantFiled: October 12, 2006Date of Patent: February 15, 2011Inventor: Richard F. Hobson