Abstract: A static content addressable memory (CAM) cell. The CAM cell includes a latch having complementary data nodes capacitively coupled to ground, first and second access transistors, each coupled between a data node of the latch and a respective data line. The gates of each access transistor is coupled to a word line such that when activated, the respective data node and data line are coupled. The CAM cell further includes a match circuit coupled to one of the complementary data nodes of the latch. The match circuit discharges a match line in response to a data value stored at the data node to which the match circuit is coupled and compare data present on the respective data line mismatching. Two of the CAM cells can be used to implement a full ternary CAM cell.

Abstract: An auxiliary voltage generation circuit is part of a high voltage generation and regulation circuit. The auxiliary voltage generation circuit generates an auxiliary intermediate voltage that is coupled to a negative level shifting circuit to reduce the drain-source stress experienced by transistors in that circuit that are in an off state. The auxiliary voltage generation circuit also generates a logic control signal that indicates to a high voltage discharge path to perform either a slow discharge operation or a fast discharge operation.

Abstract: A reading circuit for reading information stored in a memory cell includes a current supply circuit for supplying a current to a bit line connected to the memory cell; a comparison circuit for comparing a potential of the bit line supplied with the current by the current supply circuit with a reference potential so as to output the information stored in the memory cell; a disconnection circuit for electrically disconnecting the comparison circuit and the memory cell from each other under a prescribed condition; a charge circuit for charging the bit line, the charge circuit stopping charging of the bit line when the potential of the bit line exceeds a prescribed potential; and a discharge circuit for discharging the bit line when the potential of the bit line exceeds the prescribed potential.

Abstract: A programmable soft-start control circuit having two memory registers for regulating the ramp-up time period of charging current in a charge pump of an integrated circuit. The two memory registers are programmed to provide two different soft-start settings for two distinct charge pump turn-on conditions, initial power-up and flash programming. Charge pump feedback logic is employed to detect the charge pump turn-on condition and activate the proper pre-programmed soft-start setting loaded in the memory registers.

Abstract: An apparatus comprising a first plurality of parallel switches and a second plurality of parallel switches. The first plurality of parallel switches may be configured to control a voltage on a first output pin. The second plurality of parallel switches may be configured to control a voltage on a second output pin. The first and second pluralities of parallel switches may be configured to provide rise time control of a differential waveform and be driven by a phased data signal.

Abstract: A magnetic random access memory (MRAM) includes an array of magnetic memory cells arranged on a cross-point grid. Spurious voltages that build up on the stray wiring capacitance of unselected bit and word select lines are limited and discharged by diodes. The control of such spurious voltages improves device operating margins and allows the construction of larger arrays.

Abstract: A semiconductor memory device comprises a plurality of memory cell arrays, a plurality of sense amplifiers, a connection unit, a driver and an over-driver. The plurality of memory cell arrays comprise a plurality of memory cells. The plurality of sense amplifiers sense and amplify data stored in the plurality of memory cells. The connection unit selectively connects the plurality of sense amplifiers to the plurality of memory cell arrays. The driver drives the sense amplifier to a predetermined voltage. The over-driver applies an overdrive voltage to the driver for a predetermined time after the sense amplifier is temporarily separated from the selected memory cell array. In the semiconductor device since data in a bitline can be rapidly amplified, the restoration time of data stored in a memory cell is reduced, and the parameter tRCD. Accordingly, the operation speed of the semiconductor memory device can be improved.

Abstract: A system and method for coupling read data signals and write data signals through I/O lines of a memory array. Precharge circuits precharge alternating signal lines to high and low precharge voltages. An accelerate high circuit coupled to each of the I/O lines that has been precharged low detects an increase in the voltage of the I/O line above the precharge low voltage. The accelerate high circuit then drives the I/O line toward a high voltage, such as VCC. Similarly, an accelerate low circuit coupled to each of the I/O lines that has been precharged high detects a decrease in the voltage of the I/O line below the precharge high voltage. The accelerate low circuit then drives the I/O line to a low voltage, such as ground.

Abstract: An integrated circuit memory device is designed to perform high speed data write cycles. An address strobe signal is used to latch a first address. During a burst access cycle the address is incremented internal to the device with additional address strobe transitions. A new memory address is only required at the beginning of each burst access. Read/Write commands are issued once per burst access eliminating the need to toggle the Read/Write control line at the device cycle frequency. A transition of the Read/Write control line during a burst access is used to terminate the burst access and initialize the device for another burst access. Write cycle times are maximized to allow for increases in burst mode operating frequencies. Local logic gates near a nay sense amplifiers are used to control write is data drivers to provide for maximum write times without crossing current during input/output line equilibration periods.

Abstract: Disclosed is a method and structure that controls an output driver by generating an output data path clock signal from a system clock signal and timing the programmable impedance of the output driver according to the output data path clock signal. The method/structure controls the timing of the line driver circuits according to the output data path clock signal. By timing the programmable impedance according to the output data path clock signal, the timing of delivery of an impedance control signal is coordinated with the timing of delivery of data. The method/structure also performs impedance updates on the output driver more frequently during initialization cycles than in cycles that occur after the initialization cycles expire using at least two differently timed clock dividers and a counter.

Abstract: The problem of bit disturb is reduced by discharging the floating bit lines of a nonvolatile memory array during programming. An illustrative virtual ground memory array uses single transistor floating gate type memory cells that are programmed using Fowler-Nordheim (“FN”) tunneling, highly conductive and lengthy bit lines, buried and relatively short sub-bit lines and a programming discharge circuit for controlling spurious voltages on the bit lines that can arise when some of the bit lines are left floating during programming. Discharge control transistor respectively coupled to the bit lines direct current into a discharge section. A discharge section may be provided for each bit line, or shared by all bit lines. The discharge section may be a fixed circuit section for use through the programming process or may be selected from multiple discharge options.

Abstract: A discharge device comprising a transistor configured as a source follower, a capacitance load to be discharged connected via a switch to a source terminal of the source follower, a reference voltage connected to a gate terminal of the source follower, and a current load element connected to a drain terminal of the source follower.

Abstract: A sensing circuit including a sense amplifier to resolve a data signal generated by a memory cell is disclosed herein. The sensing circuit includes a bit line to receive the data signal, a first pre-charge device coupled to the bit line and configured to pre-charge the bit line, a device for providing a bias coupled to the bit line and configured to provide a bias to the bit line, and a reference node configured to be at least one pre-determined level. In one embodiment the pre-determined level is equal to a low potential such as ground and in another embodiment equal to a high potential such as VDD. One or more switching devices allows for the activation or deactivation of the pre-charge device allowing to pre-charge the bit line to a certain potential and the sensing circuit quickly and accurately determines whether a logical state of ‘1’ or ‘0’ is being applied to the bit line.

Abstract: An integrated charge sensing scheme for sensing the resistance of a resistive memory element is described. The current through a resistive memory cell is used to charge a capacitor coupled to a digit line. The voltage on the capacitor, which corresponds to the voltage on the digit line, is applied to one input of a comparator. When the voltage on the bit line exceeds a predetermined fixed voltage applied to the second input to the comparator less an offset, the comparator switches logic state, charge is drawn off from the capacitor and the capacitor charges again. The process of charging and discharging the capacitor occurs during a predetermined time period and the number of times the capacitor switches during the time period represents the resistance of the memory element.

Abstract: A charge recycling circuit is driven to raise a potential of a restore node and a sensing bar node to a given potential before a sensing operation is performed. After the sensing operation is performed, electric charges discharged from the restore node and from the sensing bar node are stored using the charge recycling circuit and can then be used when a next sensing operation is performed. Therefore, current consumed when the sensing operation is performed can be reduced and the power consumption can be thus reduced.

Abstract: A semiconductor memory device and a method for pre-charging the same, the semiconductor memory device comprising a plurality of memory cell array blocks, each having a plurality of memory cells connected between respective bit line pairs and respective word line pairs, a plurality of pairs of data input/output lines connected to the respective bit line pairs for transferring data, a first pre-charge circuit for pre-charging the bit line pairs to a first pre-charge voltage during a first operation, a second pre-charge circuit for pre-charging the data input/output line pairs and the first pre-charge voltage to the first pre-charge voltage during the first operation, a plurality of third pre-charge circuits, each being disabled in the first operation and pre-charges the data input/output line pairs in the corresponding memory cell array blocks to a second pre-charge voltage during a second operation, and a discharging circuit for lowering the first pre-charge voltage when the first pre-charge voltage is greater

Abstract: Sensing operations involving a first array of bit line sense amplifiers (BLSAs) may be powered by an upper reference voltage and a first intermediate voltage and the first array may be precharged to a voltage level therebetween. Sensing operations involving a second array of BLSAs may be powered by a second intermediate voltage (greater than the first intermediate voltage) and a lower reference voltage and the second array may be precharged to a voltage level therebetween. After precharge, charge may be transferred from a second power line of the first array to a first power line of the second array. Subsequently, the second power line of the first array may be coupled to a power supply node at the first intermediate voltage level and the first power line of the second array may be coupled to a power supply node at the second intermediate voltage level.

Abstract: A ferroelectric memory includes wordlines that cross over bitlines with a ferroelectric cell at each crossing. When reading a select cell of the array, sneak currents are drawn from an active bitline. An integration amplifier begins integrating charge propagated by the active bitline, and an active wordline receives a read level voltage. A first integration value is then obtained from the integration amplifier. Following the first integration, the integration amplifier is cleared and the voltage of the active wordline reduced to a quiescent level. Integration and wordline activation are again performed to obtain a second integration value. The second value is subtracted from the first, and the difference compared to a threshold to determine a data value.

Abstract: A CAM match detection circuit that maintains established levels of accuracy while greatly reducing the amount of power dissipated is disclosed. Rather than allowing the Matchline 185 voltage to swing between a precharge voltage level of VDD and ground, the Matchline voltage is restricted to swinging between a reduced precharge voltage level (i.e., a voltage level lower than VDD) and ground. Further, a source of a p-type transistor that makes up one transistor in each pair of series connected transistors is coupled to the Matchline thereby further reducing the Matchline swing voltage and the overall power dissipation of the match detection circuit.

Abstract: An erase discharge circuit in a flash memory is coupled to an array source and a p-well drive and receives first and second discharge signals. The erase discharge circuit operates during a discharge cycle in a first mode in response to the first discharge signal to couple the first node to the second node and to discharge voltages on the first and second nodes at a first rate. The erase discharge circuit operates in a second mode in response to the second discharge signal to couple the first node to the second node to discharge the voltages on the first and second nodes at a second rate.

Abstract: In a semiconductor memory device having a plurality of memory cells grouped in memory banks, each memory bank having a plurality of memory blocks accessible by a common row address, a method of reading from or writing to the plurality of memory blocks, comprising the steps of detecting successive read or write operations of different blocks, prefetching the address of the next block to be read or written during the first of the successive read or write operations; and withholding a precharge of the memory bank having the successively read or written memory blocks after the first of the successive read or write operations until completion of the successive read or write operations.

Abstract: A method and apparatus for discharging global bitlines in a flash memory to a voltage sufficiently low to avoid drain disturb for non-selected cells in a programming operation. A discharge device allows discharge of global bitlines coupled to local bitlines before a programming operation.

Abstract: A memory cell array is composed of a plurality of blocks separated in column direction every three word lines. Inter-block bit wires are arranged. Each inter-block bit line connects a middle diffusion wire for one of the memory cell units of first block of the separated blocks and the middle diffusion wire for one of the memory cell units of the adjacent second block lying on the other end side of the diffusion wires of the first block. Inter-block ground wires are arranged. Each inter-block ground wire connects the boundary diffusion wire for the one memory cell unit of the first block and the boundary diffusion wire for the one memory cell unit of the adjacent third block lying on the one end side of the diffusion wires of the first block.

Abstract: A sensor for a switching circuit detects the logical state of the switching circuit by monitoring the current flow through the switching circuit. The current flow is conditioned by one or more current limiters and a voltage regulator, coupled in series with the switching circuit. The sensor also includes a current limit control circuit coupled to each of the current limiters. The sensor is effectively shielded from the effect of parasitic capacitance in the switching device because the current flow through the switching circuit reacts immediately and without regard to the level of parasitic capacitance whenever the switching circuit makes a state change.

Abstract: A voltage booster device to selectively assume an active status and a stand-by status with a first terminal to assume a respective electric potential and associated to a first capacitor, a second terminal associated to a second capacitor and selectively connectable to the first terminal, and a discharge circuit for discharging the first capacitor thus reducing the electrical potential of the first terminal, the discharge circuit being activated when said device is in the stand-by status and the second terminal is disconnected from said first terminal.

Abstract: According to some embodiments, provided are a memory cell, a bit-line coupled to the memory cell, a pre-charge circuit coupled to the bit-line to pre-charge the bit-line, and a discharge device coupled to the bit-line to discharge the bit-line prior to a read of the memory cell.

Abstract: A technique to encode a precharge command on a flag signal used to execute data transfer to and from a DRAM.

Abstract: A NAND EEPROM having a shielded bit line architecture reduces supply voltage and ground noise resulting from charging or discharging bit lines. The EEPROM has a PMOS pull-up transistor and an NMOS pull down transistor connected to a virtual power node. A control circuit for charging or discharging bit lines controls the gate voltage of the PMOS or NMOS transistor to limit peak current when charging or discharging bit lines via the virtual power node. In particular, the control circuit operates the PMOS or NMOS transistor in a non-saturation mode to limit current. One such control circuit creates a current mirror or applies a reference voltage to control gate voltages. A programming method sets up bit lines by pre-charging unselected bit lines via the PMOS pull-up transistor having controlled gate voltage while latches in the programming circuitry charge or discharge selected bit lines according to respective data bits being stored. Another bit line setup includes two stages.

Abstract: A semiconductor memory storage is disclosed, in which the gate of each of a plurality of n-channel transistors is connected to the corresponding one of a plurality of word lines on the output side of each word line driver. The source of the n-channel transistor is connected through a selective switching element to the gate of the corresponding one of a plurality of replica transistors connected to a dummy bit line. The gate of each replica transistor is connected to the corresponding one of discharge transistors. The dummy bit line is connected to a sense amplifier through a logic gate.

Abstract: A system and method for effectively implementing a high-speed DRAM device may include memory cells that each have a bitline for transferring storage data, a wordline for enabling an accelerated-write operation in the memory cell, and a data storage node with a corresponding cell voltage. An accelerated-write circuit may then directly provide the storage data to an appropriate bitline in a pre-toggled state in response to one or more accelerated-write enable signals. The corresponding cell voltage may therefore begin a state-change transition towards the pre-toggled state immediately after the wordline is activated to successfully reach a full-state level before the wordline is deactivated during a high-speed memory cycle.

Abstract: A method and apparatus is disclosed for sensing the resistance state of a Programmable Conductor Random Access Memory (PCRAM) element using complementary PCRAM elements, one holding the resistance state being sensed and the other holding a complementary resistance state. A sense amplifier detects voltages discharging through the high and low resistance elements to determine the resistance state of an element being read.

Abstract: A tertiary CAM cell with three bits of storage, the three bits of storage are arranged to support three stable states which can be read from the CAM cell without requiring a charge restoration operation. The three stables states are those states where one of the three bits is at a first logical state while the remaining two bits are at a second logical state. The three stables states may be used to encode the three logical states used in a ternary CAM.

Abstract: A programmable soft-start control circuit having two memory registers for regulating the ramp-up time period of charging current in a charge pump of an integrated circuit. The two memory registers are programmed to provide two different soft-start settings for two distinct charge pump turn-on conditions, initial power-up and flash programming. Charge pump feedback logic is employed to detect the charge pump turn-on condition and activate the proper pre-programmed soft-start setting loaded in the memory registers.

Abstract: A digital memory system (30) includes a memory cell (10), a bit line (12), a voltage generator (320) and a controller (90). The controller is arranged to store a predetermined logical value in the cell by generating a series of the operating voltages beginning with the first voltage and continuing with successively larger operating voltages greater the first voltage. The voltages are transmitted to the cell from the voltage generator. After each transmittal of one of the series of operating voltages, the controller causes at least a portion of the charge stored in the cell to flow in the bit line. The controller determines whether the predetermined one of the logical values has been stored in the cell in response to the flow of charge. The controller terminates transmittal of the series of operating voltages to the cell in the event that the predetermined one of the logical states has been stored or in the event that one of the series of successively larger operating voltages equals the second voltage.

Abstract: A sensor for a switching circuit detects the logical state of the switching circuit by monitoring the current flow through the switching circuit. The current flow is conditioned by one or more current limiters and a voltage regulator, coupled in series with the switching circuit. The sensor also includes a current limit control circuit coupled to each of the current limiters. The sensor is effectively shielded from the effect of parasitic capacitance in the switching device because the current flow through the switching circuit reacts immediately and without regard to the level of parasitic capacitance whenever the switching circuit makes a state change.

Abstract: An equalizing and precharging circuit in a semiconductor memory device includes a pull down equalizing and precharging unit for equalizing and precharging data lines in response to an input/output equalizing signal and a pull up equalizing and precharging unit for equalizing and precharging data lines in response to an input/output equalizing bar signal.

Abstract: The invention includes an apparatus and method of selecting memory cells within a memory array. The method includes receiving a memory cell address. A column address and a row address are generated from the memory cell address. Row select lines or column select lines are pre-charged. A self-timed charging circuit is initiated to provide an adequate amount of time to charge a selected row, and to initiate elimination of static current flowing to unselected rows after a self-timed delay. The other of the row select lines or the column select lines are then pre-charged. Memory cells are selected based upon the column address and the row address. One of two states of the memory cells can be based upon sensing threshold voltages of sense lines that correspond with the selected memory cells.

Abstract: The present invention relates to a flash memory device for read-out. The flash memory device comprises a pumping circuit for generating a pumping voltage higher than the power supply voltage depending on an enable signal generated when a standby mode, a read-out mode and a power supply voltage are set up, a capacitor for charging the potential depending on the pumping voltage of the pumping circuit, a word line decoder and a bit line decoder for decoding an address signal to select a word line and a bit line of a given cell from the flash memory cell array, and a word line driver and a bit line driver for applying a given voltage depending on an electric charge stored at the capacitor to the word line and the bit line of the selected cell in the flash memory cell array so that a read-out operation is performed. At this time, a voltage depending on the charge stored at the capacitor is applied to the word line driver and the bit line driver in the read-out mode.

Abstract: After data readout, in equalizing a complementary pair of bit lines one of which has been overdriven with an overdrive voltage, excessive charges on the overdriven bit line are discharged by a discharge circuit. By adjusting the discharge period of the discharge circuit, the potential to which the bit lines are equalized is adjusted.

Abstract: A NAND EEPROM having a shielded bit line architecture reduces supply voltage and ground noise resulting from charging or discharging bit lines. The EEPROM has a PMOS pull-up transistor and an NMOS pull down transistor connected to a virtual power node. A control circuit for charging or discharging bit lines controls the gate voltage of the PMOS or NMOS transistor to limit peak current when charging or discharging bit lines via the virtual power node. In particular, the control circuit operates the PMOS or NMOS transistor in a non-saturation mode to limit current. One such control circuit creates a current mirror or applies a reference voltage to control gate voltages. A programming method sets up bit lines by pre-charging unselected bit lines via the PMOS pull-up transistor having controlled gate voltage while latches in the programming circuitry charge or discharge selected bit lines according to respective data bits being stored. Another bit line setup includes two stages.

Abstract: A memory controller is disclosed, in which upon receipt of an access request from a device, the memory controller activates a page designated by a row address of a first bank at a predetermined memory cycle, based on the access request. After that, before the read access to a page of the first bank, a second bank next to be accessed is precharged. In the case where a page mishit occurs due to the access from the first bank to the second bank by the graphic processing after the access to the first bank by the read operation, the memory controller activates the second bank immediately without precharging.

Abstract: A system and method for coupling read data signals and write data signals through I/O lines of a memory array. Precharge circuits precharge alternating signal lines to high and low precharge voltages. An accelerate high circuit coupled to each of the I/O lines that has been precharged low detects an increase in the voltage of the I/O line above the precharge low voltage. The accelerate high circuit then drives the I/O line toward a high voltage, such as VCC. Similarly, an accelerate low circuit coupled to each of the I/O lines that has been precharged high detects a decrease in the voltage of the I/O line below the precharge high voltage. The accelerate low circuit then drives the I/O line to a low voltage, such as ground.

Abstract: The present disclosure relates to a semiconductor memory device. A charge recycling circuit is driven to raise a potential of a restore node and a sensing bar node to a given potential before a sensing operation is performed. After the sensing operation is performed, electric charges discharged from the restore node and from the sensing bar node are stored using the charge recycling circuit and can then be used when a next sensing operation is performed. Therefore, current consumed when the sensing operation is performed can be reduced and the power consumption can be thus reduced.

Abstract: An apparatus comprising an array of memory cells, a refresh circuit, a first monitor cell, a second monitor cell, and a control circuit. The refresh circuit may be configured to refresh the array of memory cells in response to a refresh control signal. The first monitor cell may be configured to have a charge leakage similar to the memory cells. The second monitor cell may be configured to have a discharge leakage similar to the memory cells. The control circuit may be configured to generate the refresh control signal in response to either a voltage level of the first monitor cell rising above a first pre-determined threshold level or a voltage level of the second monitor cell dropping below a second pre-determined threshold level, where the first and second threshold levels are different.

Abstract: An erase discharge circuit in a flash memory is coupled to an array source and a p-well drive and receives first and second discharge signals. The erase discharge circuit operates during a discharge cycle in a first mode in response to the first discharge signal to couple the first node to the second node and to discharge voltages on the first and second nodes at a first rate. The erase discharge circuit operates in a second mode in response to the second discharge signal to couple the first node to the second node to discharge the voltages on the first and second nodes at a second rate.

Abstract: A semiconductor device having a first circuit block supplied with a first operating voltage, a second circuit block supplied with a second operating voltage, a voltage generating circuit for generating a third operating voltage in response to the first operating voltage, and a third circuit block supplied with the third operating voltage. Preferably, the third operating voltage is generated such that the first operating voltage is increased to a fourth operating voltage by a voltage-up converter, and then the fourth operating voltage is dropped to the third operating voltage by a voltage down-converter. Hence, a power supply operating internally stably in spite of use of a relatively fluctuating voltage can be provided even in the case where a power-supply voltage is dropped.

Abstract: A method for reading a memory cell comprising the steps of (A) raising a voltage level of a bitline of the memory cell above a predetermined level, (B) detecting a current flow generated on the bitline in response to the raised voltage level, and (C) coupling one or more sense nodes coupled to the bitline to a ground potential when the current flow is above a predetermined magnitude.

Abstract: A content addressable memory (CAM)(10, 102) and method having a data-in sub-circuit (44), memory cells (16, 18), a match-high line (36), a match-low line (38), and pre-charge devices (40, 42). Input lines (30, 32, 48, 50) from the data-in sub-circuit (44) are not necessarily discharged to ground in every cycle of a clock signal (62) used by the memory cells (16, 18). Further, the pre-charge devices (40, 42) may be operated at one half of the rate of the clock signal (62). Yet further, the CAM (10, 102) may be selectively configured to operate in either binary or ternary mode.

Abstract: A method and apparatus for improving time between row address latching and column address latching (tRCD) by allowing the pull-up of the IO lines during a READ burst to end upon the firing of a column access signal rather than waiting for the next clock signal of the READ operation. A latch is set during the active command in order to set a node voltage which allows the IO pull-up signal to end upon the firing of the column access signal. The invention allows improvement in tRCD parameter, and allows digit line pairs to separate without unwanted line sharing with the IO lines prior to reading of the first bit of a data burst. The result is a more accurate and error-free read of a first bit of data during a READ sequence.

Abstract: A CAM circuit utilizes a relatively high operating voltage to control the memory portion of each CAM cell, and a relatively low operating voltage to control at least some of the logic portions of each CAM circuit. The CAM cell memory portion includes a memory (e.g., SRAM) cell controlled by a word line to store data values transmitted on complementary bit lines. The CAM cell logic portion includes a comparator that compares the stored data values with an applied data value transmitted on complementary data lines, and discharges a match line when the stored data value differs from the applied data value. The memory cell is driven using the relatively high memory operating voltage (e.g., 2.5 Volts) such that the stored charge resists soft errors. The complementary data lines and match line used to operate the comparator are driven using the relatively low logic operating voltage (e.g., 1.2 Volts) to conserve power.