Abstract: A CAM circuit according to the present invention used for a cash memory and the like, wherein an address is obtained by designating a data, comprises a data compare unit for comparing a data stored in a memory unit to a data of a compare line in a state where a match line is activated and a consistency cancel circuit for forcibly making the match line inactive when a word line and a write instruction signal are both activated. When a write operation and a retrieve operation are simultaneously instructed, a result of the retrieval is forcibly judged to be inconsistent at a write address, thereby it is unnecessary to prohibit the simultaneous execution of the write operation and the retrieve operation.

Abstract: A semiconductor non-volatile memory device, particularly a flash memory array, having a chip configuration with a plurality of pins including a write protect pin, a serial in pin and an optional parallel data bus with input-output pins (I/O7-0), plus other pins, all electrically communicating with the memory array and particularly a sector protection register of variable size and location. The sector protection register defines which sectors or group of sub-sectors to protect and is controlled by the use of commands via the serial in pin or the optional input-output pins. The sector protection may be selectably controlled by either use of a signal to the write protect pin or use of commands via the serial in pin or the optional input-output pins to the command and control logic. A logic circuit instantly determines whether the write protect pin or the commands are controlling the sector protection.

Abstract: Methods and apparatuses for disabling a bad bitline for verification operations, and for determining whether a programming operation have failed, include setting a bitline disable latch for a bad bitline, and inhibiting operation of a program latch if the bitlines is excluded or if a programming operation fails.

Abstract: A memory chip includes a main memory cell; a row-wise redundant memory cell and a column-wise redundant memory cell for relieving a defect existing in the main memory; an identification number designation terminal for storing an identification number corresponding to the main memory cell; an address terminal for receiving the identification number; and a redundant row selector circuit and a redundant column selector circuit for performing allocation so as to replace a defective memory space of the main memory cell with a memory space of the redundant memory cells. The redundant selector circuits allocate a memory space corresponding to the defect of the main memory cell to the redundant memory cells when the identification number received from the address terminal coincides with the identification number of the identification number specification terminal.

Abstract: Provided are a buffer circuit and a memory system for selectively outputting a data strobe signal according to the number of data bits. The buffer circuit includes a first buffer unit, a second buffer unit, and a third buffer unit. The first buffer unit amplifies and outputs a first signal. The second buffer unit amplifies and outputs a second signal or outputs the first signal according to the logic level of a control signal. The third buffer unit amplifies the first signal to send or not to send the amplified first signal to the second buffer unit depending on the logic level of an inverted control signal. The logic levels of the control signal and the inverted control signal are determined according to the number of processed data bits.

Abstract: An integrated circuit memory device includes a plurality of memories and a refresh controller within a memory system. The refresh controller is configured to generate a refresh request signal. The plurality of memories includes a plurality of banks of memory responsive to the refresh request signal. An additional memory includes a buffer unit configured to generate a refresh indication signal to a first one of the plurality of banks of memory and to receive buffer write data addressed to the first one of the plurality of banks of memory in response to receiving a refresh-access interrupt signal from the one of the plurality of banks of memory. The plurality of banks of memory and the buffer unit may be separate DRAM chips.

Abstract: A dynamic random access memory (DRAM) device, including a DRAM core having memory cells for storing data information, and a read protection unit, prevents data stored in the memory cells before power-off, from being read out at power-on.

Abstract: A memory for storing data comprising a fast data reading mechanism operable to sense one or more signal values dependent upon a data value stored in said memory so as to generate a first signal transition indicative of said data value and used to generate a fast read result that is output from said memory for further processing; a slow data reading mechanism operable to sense said one or more signal values dependent upon said data value so as to generate a second signal transition indicative of said data value and used to generate a slow read result available after said fast read result, said slow read result being less prone to error than said fast read result; a comparator operable to compare said fast read result and said slow read result and to generate an error signal if said fast read result does not match said slow read result; and a timing checker coupled to said fast data reading mechanism and operable to detect that said first signal transition was generated within a predetermined time and generate

Abstract: A nonvolatile semiconductor memory device comprising a storage element which is programmed with information by varying electrical properties irreversibly, a selection switch connected in series to the storage element, a protection element connected in parallel to the storage element to protect the storage element from irreversible variations of electrical properties when the storage element is unprogrammed, a first activation circuit which activates the selection switch, a second activation circuit which activates the protection element in complement with the first activation circuit in normal mode, and a test circuit which conducts a test on the storage element while the second activation circuit is activating the protection element together with the first activation circuit in test mode.

Abstract: A semiconductor integrated circuit including one or a plurality of external functional blocks; a nonvolatile memory having a logical content as to whether to validate or invalidate the external functional blocks; and a logical circuit validating or invalidating an input and an output to each external functional block in accordance with the logical content of the memory, wherein a user is allowed to validate use of a necessary external functional block and to invalidate use of an unnecessary external functional block.

Abstract: The present invention relates to a non-volatile memory comprising a memory array comprising functional memory cells and non-functional memory cells linked to at least one non-functional word line. A word line address decoder comprises a special decoding section linked to the non-functional word line, for selecting the non-functional word line when a functional word line is read-selected, such that non-functional memory cells are selected simultaneously with the functional memory cells, and distort the reading of the functional memory cells. Application particularly to integrated circuits for smart cards.

Abstract: An apparatus and method for selecting a storage location in a memory device including receiving at least one of a pre-decoded location address signal, a match signal, and a redundant location address enable signal, enabling one of a decoder and a redundant decoder in response to the match signal, wherein the decoder is operable to generate a location select signal for selecting a first location, the decoder being responsive to the pre-decoded location address signal, and wherein the redundant decoder is operable to generate a redundant location select signal for selecting a second location, the redundant decoder being responsive to the redundant location address enable signal, and terminating one of the generation of a location select signal and the generation of a redundant location select signal in response to a precharge signal.

Abstract: A semiconductor memory device includes a plurality of first fuse latch circuits configured to provide redundancy to first addresses, a plurality of second fuse latch circuits configured to provide redundancy to second addresses, and a nullifying circuit configured to make the plurality of second fuse latch circuits ineffective, wherein first fuse positions corresponding to the plurality of first fuse latch circuits intervene between second fuse positions corresponding to the plurality of second fuse latch circuits.

Abstract: A semiconductor device includes a first memory cell array that includes memory cells for storing data and is managed on a sector basis, a second memory cell array including memory cells storing sector protection information on the sector basis, and a control circuit checking the sector protection information stored in the second memory cell array whenever the sector to be programmed or erased is selected. Thus, the sector protection information in all the sectors does not have to be latched at the time of power on. The latch circuit equal in number to the sector does not have to be provided. It is thus possible to reduce the number of the circuits drastically and the chip area can be reduced.

Abstract: A non-volatile memory is programmed in a manner which reduces the incidence of program disturb for inhibited memory elements which undergo boosting to reduce program disturb, but which experience reduced boosting benefits due to their word line location. To achieve this result, a word line sequence in which the memory elements are programmed is adjusted so that higher word lines are programmed first, out of sequence relative to the remaining word lines. Additionally, self-boosting can be used for the higher word lines, while erased area self-boosting or a variant can be used for the remaining word lines. Furthermore, pre-charging of the channel of the inhibited memory elements may be employed prior to the self boosting, for the non-volatile storage elements which are programmed after those associated with the first word line.

Abstract: A semiconductor memory device includes a refresh counter that outputs an address of a word line to be refreshed, a ROM circuit that stores a relevant address related to a refresh defective address, and a multiple refresh control circuit that simultaneously or continuously activates the refresh defective address and the relevant address within one refresh cycle in response to a fact that the ROM circuit detects the relevant address. The multiple refresh control circuit excludes a pattern having a risk that a power supply potential or a ground potential varies greatly such as a pattern that the multiple refresh occurs continuously. With this arrangement, a refresh defective cell can be saved while restricting the variation in the power supply potential or the ground potential.

Abstract: The effects of bit line-to-bit line coupling in a non-volatile memory are addressed. An inhibit voltage is applied on a bit line of a storage element to be programmed to inhibit programming during a portion of a program voltage. The inhibit voltage is subsequently removed during the program voltage to allow programming to occur. Due to the proximity of bit lines, the change in the bit line voltage is coupled to a neighboring unselected bit line, reducing the neighboring bit line voltage to a level which might be sufficient to open a select gate and discharge a boost voltage. To prevent this, the select gate voltage is temporarily adjusted during the change in the bit line voltage to ensure that the biasing of the select gate on the unselected bit line is not sufficient to open the select gate.

Abstract: A method for storing of a plurality of data blocks in a digital rewritable memory of semiconductors controlled by a memory manager and includes the steps of: randomly determining an available area; and storing the data block in the area determined in the determining step. This method of data storage is preferably applied to chip cards and to similar electronic modules. It prevents the reproduction of the functionalities of the card after an analysis of the contents of the memory. Furthermore, it assures a better distribution of the wearing of the memory.

Abstract: An integrated circuit having a device with an adjustable parameter utilizes a two signal control protocol to select the device, perform an up/down or increment/decrement of the parameter value with or without saving the parameter value in a non-volatile memory of the integrated circuit.

Abstract: A data processing system (10) has an embedded non-volatile memory (22) that is programmed and erased by use of a high voltage provided by a charge pump (78). In order to prevent the non-volatile memory (22) from being inadvertently programmed or erased during low power supply voltage conditions, the charge pump (78) is disabled and discharged when the power supply voltage drops below a predetermined value. This is accomplished by enabling a low voltage detect circuit (110) in response to a program or erase operation being initiated. A control register (76) will provide a high voltage enable signal to the charge pump (78) only when a power supply valid signal is received. In another embodiment, the low voltage detect circuit (110) may be enabled by another condition to protect the data processing system (10) from an authorized access.

Abstract: A self refresh circuit includes a refresh control unit and an internal refresh circuit. The refresh control unit generates a refresh control signal based on a refresh period pulse when a MRS (Mode Set Register) command is deactivated, interrupts an output of the refresh control signal based on a self-refresh-entrance inhibiting signal when the MRS command is deactivated, and generates a refresh command regardless of the refresh period pulse when the MRS command is activated. The MRS command is generated by a combination of at least one address signal and at least one control signal. The internal refresh circuit performs a refresh operation based on the refresh command. Accordingly, access time may be measured correctly and test time may be reduced.

Abstract: The invention relates to a method for erasing non-volatile memory cells, and to a corresponding non-volatile memory device of the programmable and electrically erasable type implementing the method, and comprising a memory cell array organized in a row-and-column layout, and divided in array sectors, including at least one row decode circuit portion being supplied positive and negative voltages. The method is applied whenever the issue of the erase algorithm is negative, and comprises the following steps: forcing an incompletely erased sector into a read condition; scanning the rows of said sector to check for the possible presence of a spurious current indicating a fail state; identifying and electrically isolating the failed row; re-addressing from said failed row to a redundant row provided in the same sector; re-starting the erase algorithm.

Abstract: Disclosed herein is a word line driving circuit in which sub-word lines are prevented from floating by using a sub-word line driver having two transistors. A plurality of sub-word line drivers is connected to one main word line. Each of the plurality of the sub-word lines includes a PMOS transistor and a NMOS transistor serially connected between a sub-word line driving voltage FX and a ground voltage. A floating prevention unit selects the main word line to a level of a threshold voltage using a driving signal having the level of the threshold voltage, thus preventing sub-word lines of a sub-word line driver, where the sub-word line driving voltage FX is off, from floating.

Abstract: A data processor includes an authentication circuit for judging access right. The data processor further includes a nonvolatile memory cell array formed on an insulator film of a chip, and a conductor layer provided between a logic circuit of the authentication circuit and the nonvolatile memory cell array. The nonvolatile memory cell array can store at least part of authentication information or an authentication program.

Abstract: A device and a method for breaking the leakage current path, wherein the leakage current is caused by a defect in a memory cell of a memory array, are provided. The device includes a column selection line, a row selection line, a switch device coupled to the column selection line, the row selection line, a power supply terminal and a memory cell. When a column turn-off signal is coupled to the column selection line and a row turn-off signal is coupled to the row selection line, the switch device is turned off and thus a power from the power supply terminal can not be coupled to the memory cell. When at least one of the column selection line and the row selection line does not receive the turn-off signal, the switch device is not turned off and the power can be coupled to the memory cell.

Abstract: A non-volatile memory is programmed in a manner which reduces the incidence of program disturb for inhibited memory elements which undergo boosting to reduce program disturb, but which experience reduced boosting benefits due to their word line location. To achieve this result, a word line sequence in which the memory elements are programmed is adjusted so that higher word lines are programmed first, out of sequence relative to the remaining word lines. Additionally, self-boosting can be used for the higher word lines, while erased area self-boosting or a variant can be used for the remaining word lines. Furthermore, pre-charging of the channel of the inhibited memory elements may be employed prior to the self boosting, for the non-volatile storage elements which are programmed after those associated with the first word line.

Abstract: A current reduction circuit of a semiconductor device is disclosed which includes an enabling signal generator which outputs a predetermined enabling signal in association with a cell block in which a bridge has been formed between a word line and a bit line, and an isolation controller which is enabled in response to the enabling signal, and outputs a control signal to periodically isolate the bridge-formed cell block from a sense amplifier array for a predetermined period in a standby mode in response to a periodic signal enabled at intervals of a predetermined time.

Abstract: A non-volatile memory system is programmed so as to reduce or avoid program disturb. In accordance with one embodiment, the storage elements of a NAND string are partitioned into at least two regions. A first boosting voltage is applied to the first region of the string while a second larger boosting voltage is applied to the second region. The first region includes the addressed row or selected word line for programming. The boosting voltages are applied to the NAND strings of a block while the NAND strings are being inhibited from programming. In this manner, the second boosting voltage can be made larger without inducing program disturb on the memory cells receiving the larger boosting voltage. The boosted voltage potentials of the NAND string channels are trapped within the first region by lowering the boosting voltage on one or more bounding rows. The second boosting voltage is then lowered and data is applied to the bit lines of the NAND strings to select the appropriate strings for programming.

Abstract: A storage device comprises a memory element and an applying unit for applying a voltage to the memory element wherein the memory element changes its characteristic to record thereon information with application of a voltage to the memory element by the applying unit, the memory element further changing its characteristic when the same information is recorded on the memory element continuously. The memory element has a recording method which comprises the steps of detecting content of information that has already been recorded on the memory element when the information is recorded, comparing the information that has already been recorded on the memory element with information to be recorded on the memory element, applying a voltage to the memory element to make an ordinary information recording process if the two information are different from each other and disabling the ordinary information recording process when the two information are identical to each other.

Abstract: A secure memory device that is configured to prevent unauthorized access of data is disclosed. More specifically, a kill function logic device is capable of initiating security measures upon the occurrence of some event. The security measures may include disabling read access to the memory device, accelerated erasing of the memory device, or disabling of the memory device itself. Alternatively, a circuit may be configured to purge data stored in the memory device in an accelerated fashion.

Abstract: A microcomputer with a built-in non-volatile semiconductor memory, which can automatically perform a work of temporarily interrupting automatic writing or automatic erase and accepting an interruption process when an interruption occurs during the automatic writing or automatic erase by using an interrupt request signal for a microcomputer as an external input for controlling automatic writing or automatic erase of a flash memory.

Abstract: A secure command is entered into a Flash memory device. A control data word is written to the memory device to specify which blocks of memory are to be permanently secured against write and erase operations. The bits of the control data word specify different blocks of memory to be permanently secured.

Abstract: A method and system for storing secure data in a multi-time programmable, non-volatile electrically-alterable memory device are disclosed. Accordingly, in an embodiment, a memory device may include a data register with a fixed N-bit pattern, comparator logic, control logic, and an array of non-volatile electrically-alterable memory cells. Each memory cell includes a floating gate to store an electronic charge representing the logical state of the memory cell. The plurality of memory cells may be logically partitioned to include an N-bit secure lock and a plurality of memory cells for storing secure data. The random bit values stored in the N-bit secure lock are read, and compared with the fixed N-bit pattern stored in the data register. If the N-bit patterns do not match, the control logic allows the plurality of memory cells for storing secure data to be programmed with secure data.

Abstract: To reduce the size and the power consumption of a semiconductor device. A first circuit having a prescribed circuit function is provided. A second circuit which can be connected to the first circuit externally gives the first circuit a non-always-used particular function so that the first circuit can perform the particular function.

Abstract: A semiconductor device of this invention includes an initialization circuit for initializing a predetermined circuit in accordance with the level of a power source voltage, and a status setting unit for setting the status of the semiconductor device to “busy” during a period in which the initialization circuit performs initialization.

Abstract: Provided are a buffer circuit and a memory system for selectively outputting a data strobe signal according to the number of data bits. The buffer circuit includes a first buffer unit, a second buffer unit, and a third buffer unit. The first buffer unit amplifies and outputs a first signal. The second buffer unit amplifies and outputs a second signal or outputs the first signal according to the logic level of a control signal. The third buffer unit amplifies the first signal to send or not to send the amplified first signal to the second buffer unit depending on the logic level of an inverted control signal. The logic levels of the control signal and the inverted control signal are determined according to the number of processed data bits.

Abstract: An FCRAM includes first to third circuits. The first circuit generates a first signal based on a command detection signal. The second circuit is configured to receive the command detection signal, an operation mode specifying signal and a selection signal and generate a second signal which causes the start timing of the operation of a row-system circuit to be synchronized with the input timing of a second command. The third circuit is configured to select the first signal when a normal operation mode is specified by the operation mode specifying signal, select the second signal when a test mode is specified, and generate a third signal used to activate at least part of the memory cells in a memory cell array based on a selected one of the first and second signals and the selection signal.

Abstract: A semiconductor device includes a memory cell array, including at least one of a plurality of memory cells storing program data received from a flash memory, a row address buffer, which receives a row address signal in response to a first strobe signal, and a column address buffer, which receives a column address signal in response to a second strobe signal. The device further includes a write protection circuit, enabled/disabled in response to a first control signal, the write protection circuit outputting a masking control signal in response to the row address signal, the second strobe signal, and second control signals when enabled, and a column decoder, which decodes the column address signal in response to the masking control signal and enables at least one of a plurality of column selection lines of the memory cell array, corresponding to the decoded column address signal, or disables the column selection lines.

Abstract: A control circuit in a semiconductor memory device accessing a memory cell for a plurality of cycles includes an internal command generating circuit and a mask signal generating circuit. Upon receiving a control command, the internal command generating circuit outputs an internal signal instructing an operation to access the memory cell at H level when a mask signal is at L level, while outputs an internal signal at L level when the mask signal is at H level, because a latch circuit is reset. The mask signal generating circuit outputs the mask signal at H level for a following cycle, when the internal signal is output at H level.

Abstract: An integrated circuit having a device with an adjustable parameter utilizes a two signal control protocol to select the device, change the parameter value with or without saving the parameter value in a non-volatile memory, and to write protect the parameter value in the non-volatile memory.

Abstract: A semiconductor non-volatile memory device, particularly a flash memory array, having a chip configuration with a plurality of pins including a write protect pin, a serial in pin and an optional parallel data bus with input-output pins (I/O7-0), plus other pins, all electrically communicating with the memory array and particularly a sector protection register of variable size and location. The sector protection register defines which sectors or group of sub-sectors to protect and is controlled by the use of commands via the serial in pin or the optional input-output pins. The sector protection may be selectably controlled by either use of a signal to the write protect pin or use of commands via the serial in pin or the optional input-output pins to the command and control logic. A logic circuit instantly determines whether the write protect pin or the commands are controlling the sector protection.

Abstract: A semiconductor storage device includes a program ROM and a flash memory, and the program ROM includes a program data storing area and a dummy data storing area, and the flash memory includes a program data storing area and a dummy address storing area. An address comparison circuit compares an input address and a dummy address being stored in the dummy address storing area with each other. An output inhibiting circuit allows to read program data from the program ROM when the both addresses are not coincident with each other, and inhibits the program data from being read at a time of incoincidence. In a case of the incoincidence, an address conversion circuit produces a read address of the flash memory, whereby the program data is read from the flash memory.

Abstract: A partial array self refresh (PASR) control apparatus for use in a semiconductor memory device having a plurality of banks includes: a bank deselection unit having a plurality of bank deselection signal output units for receiving a plurality of PASR code signals, wherein input terminal lines of each bank deselection signal output unit and signal lines of the plurality of PASR code signals are crossed each other and are selectively coupled each other.

Abstract: There is provided a semiconductor memory device in which data, stored in a unit data storage section configured by one or more data storage elements, is erased to be formed into a specific erasure data pattern. The semiconductor memory device has a data protection mechanism in which a determination is made as to whether or not data stored in the unit data storage section has the erasure data pattern, and programming of the data into the unit data storage section is inhibited when the data is not in the erasure data pattern. This mechanism can protect already programmed data from being destroyed due to programming error at the time of programming the data.

Abstract: In a prefetch-type FCRAM having an improved data write control circuit and a method of masking data using the prefetch-type FCRAM, the prefetch-type FCRAM includes a command decoder, a row decoder, a column decoder, a data input buffer, a data output buffer, and a valid write window buffer. The command decoder outputs control commands including first and second write commands in response to predetermined external input signals. The row decoder decodes a row address signal input into the address pins and activates a wordline of the memory cell array corresponding to the decoded row address signal. The column decoder decodes a column address signal input into the address pins and activates a column select line of the memory cell array corresponding to the decoded column address signal. The data input buffer receives input data from the plurality of data pins and then outputs the input data in synchronization with a predetermined clock signal.

Abstract: A memory circuit comprising a memory area for storing data, a non-volatile memory area for storing at least one identification code, and a pin for storing the identification code in the non-volatile memory area. The memory circuit further comprising a programmable register in which a programmable state is fixed, wherein the programmable state indicates if the identification code has been stored in the non-volatile memory area, and a logic module which blocks any subsequent changes to the identification code fixed in the non-volatile memory area in response to the programmable state in the programmable register indicating that the identification code has been stored in the non-volatile area. The invention also relates to an associated method. The invention is useful particularly to avoid fraudulent reprogramming of the area containing the identification code. The invention also relates to an associated method.

Abstract: An FCRAM includes first to third circuits. The first circuit generates a first signal based on a command detection signal. The second circuit is configured to receive the command detection signal, an operation mode specifying signal and a selection signal and generate a second signal which causes the start timing of the operation of a row-system circuit to be synchronized with the input timing of a second command. The third circuit is configured to select the first signal when a normal operation mode is specified by the operation mode specifying signal, select the second signal when a test mode is specified, and generate a third signal used to activate at least part of the memory cells in a memory cell array based on a selected one of the first and second signals and the selection signal.

Abstract: Using 6 transistor memory cell to replace prior art 10 transistor binary content addressable memory (CAM) cells, and using 10 transistor ternary CAM (TCAM) cell to replace prior art 16 transistor TCAM cells, the present invention provided significant cost saving for high density CAM products. The power consumption problems of prior art high density CAM devices are solved by novel zoned lookup mechanism. For a high density CAM storing sorted data, lookup mechanisms of the present invention can reduce power consumption by two orders of magnitudes.

Abstract: In a SRAM structure, power consumption is reduced by providing a structure which allows specific memory cells to be selected using word lines and column select lines, and reducing the load on the column address lines by dividing the load into sectors. The dividing into sectors is achieved by making use of sector select lines for selecting two or more rows of cells, and logically ANDing the sector select lines with the column select lines.

Abstract: Programmable logic devices (PLDs) that can be repeatedly erased and reprogrammed, e.g., during the testing and/or design phases, and then converted to one-time programmable (OTP) devices on a permanent basis, and methods of converting a PLD to an OTP device. In some embodiments, only the erase function is disabled in the device. Because programming data cannot then be erased from the device, the addition of new programming data is very unlikely to yield an operable design. Therefore, the programming function is also effectively disabled. The programming function can be directly disabled in addition to or instead of the erase function, if desired. The erase and/or programming functions can be disabled, for example, by blowing one or more fuses included in the erase and/or programming circuitry of the PLD.