Abstract: A semiconductor storage device for storing data to unit blocks of a memory cell array, comprising: two rows of sense amplifiers arranged on both sides of bit lines and each including sense amplifiers; a switch means for switching a connecting state between one row of sense amplifiers and one side of bit lines and switching a connecting state between the other row of sense amplifiers and the other side of bit lines; a control means which sets at least one row of sense amplifiers as a cache memory, and when performing refresh operation of the unit block where row of sense amplifiers to be used as cache memory holds data, controls switch means so that the row of sense amplifiers used as cache memory is disconnected from bit lines and only the row of sense amplifiers not used as said cache memory is used in refresh operation.

Abstract: A semiconductor memory device comprises word lines, global bit lines intersecting with the word lines; local bit lines partitioned into N sections along the global bit lines and aligned with a same pitch as the global bit lines; N memory cell arrays each including memory cells formed at intersections of the word lines and the local bit lines and being arranged corresponding to the sections of the local bit lines; local sense amplifiers for amplifying a signal read out from a selected memory cell to the local bit line and for outputting the signal to the global bit line; global sense amplifiers for amplifying the signal transmitted from the local sense amplifier corresponding to the selected memory cell through the global bit line and for selectively coupling the signal to an external data line.

Abstract: Each memory cell of a molecular battery memory device includes a combination of a molecular battery and a selection transistor, and a parasitic capacitance is present in the molecular battery. A PN junction is present in the selection transistor, and is inversely biased. Therefore, a junction leak current flows. Accordingly, a charge accumulated in the parasitic capacitance is gradually discharged by a junction leak of the selection transistor, and a final potential of a node decreases toward a substrate potential Vs of the transistor. However, a difference between a substrate potential Vs and a reference potential Vp (=Vs?Vp) is set substantially equal to an open-circuit voltage of the molecular battery. Because the potential of the node converges to the open-circuit voltage without exception from the viewpoint of a plate wiring, an S/N ratio at the data reading time can be increased.

Abstract: A semiconductor memory device formed on a semiconductor chip includes first memory arrays, a plurality of second memory arrays, a first voltage generator, and first bonding pads. The semiconductor chip is divided into first, second and third rectangle regions and the third rectangle region is arranged between the first rectangle region and the second rectangle region. The first memory arrays are formed in the first rectangle region. The second memory arrays are formed in the second rectangle region. The voltage generator and first bonding pads are arranged in the third rectangle region. The first bonding pads are arranged between the first rectangle region and the voltage generator and no bonding pads are arranged between the voltage generator and the second memory arrays.

Abstract: A nonvolatile RAM allows a read/write operation to be performed in a random manner with respect to a memory area, which is divided into a plurality of memory arrays each including a plurality of memory cells. Upon detection of an initialization signal, initialization is performed on at least one memory array, which is selected in advance. In addition, a disconnection control signal occurs so as to disconnect an access by an external device during a prescribed period for performing the initialization. The nonvolatile RAM is capable of protecting data from being irregularly read, modified, and reloaded with respect to at least one memory array, which is selected in advance, even when the nonvolatile RAM is frequently accessed by a prescribed application.

Abstract: A nonvolatile RAM for reading and writing data in a random manner includes a memory area configured by a plurality of memory cells suited to a nonvolatile-mode write operation, in which the stored content thereof is not lost irrespective of a power-off event, and a volatile-mode write operation, in which the stored content thereof is lost in the power-off event. A register designates a first portion of the memory area adapted to the nonvolatile-mode write operation regarding fixed data such as program codes and a second portion of the memory area serving as a work area adapted to the volatile-mode write operation. A control circuit performs the nonvolatile-mode write operation on the first portion of the memory area while performing the volatile-mode write operation on the second portion of the memory area.

Abstract: A synchronous DRAM is provided which includes arrangements for operations of power supply circuitry based upon whether the DRAM is in a power down mode or not. In one embodiment, a first power supply circuit and a second power supply circuit are provided which both receive externally supplied voltages and output internal supply voltages. The first power supply circuit is not in operation when a semiconductor device of the synchronous DRAM is in a power down mode. However, the second power supply circuit is continuously in operation during the power down mode. In another arrangement, the operation of a voltage limiter circuit is controlled based on whether or not the DRAM is in a power down mode.

Abstract: A synchronous DRAM is provided which includes arrangements for operations of power supply circuitry based upon whether the DRAM is in a power down mode or not. In one embodiment, a first power supply circuit and a second power supply circuit are provided which both receive externally supplied voltages and output internal supply voltages. The first power supply circuit is not in operation when a semiconductor device of the synchronous DRAM is in a power down mode. However, the second power supply circuit is continuously in operation during the power down mode. In another arrangement, the operation of a voltage limiter circuit is controlled based on whether or not the DRAM is in a power down mode.

Abstract: A phase change memory of high compatibility with DRAM. If a cell MC0, connected to a word line WL0L, is of a low resistance, current flowing through it is higher than that flowing in a dummy cell MR0, and hence a bit line SA_B is at a potential lower than that of a bit line SA_T. This difference is amplified by a sense amplifier SA and read out. Immediately before latching cell data by the sense amplifier, an NMOS transistor MN1 is turned off to disconnect a memory cell part from a sense amplifier part. An NMOS transistor MN10 then is turned on so that data on the selected word line are all in the set state. If then writing is to be carried out, writing is carried out in the sense amplifier SA from signal lines LIO and RIO, which are I/O lines. However, writing is not performed in the memory cells. Before a precharge command is entered to precharge the word line WL0L, under, the NMOS transistor MN1 is again turned on to write reset in the cell MC0.

Abstract: Control clocks of different phases are distributed to a memory array divided into multiple banks, and processing of entries and search keys (read and write operations and search operation) is performed at different phases. The memory array divided into banks is further divided into smaller arrays, that is, sub-arrays, and a sense amplifier in a read-write-search circuit block is shared by the two sub-arrays. In this case, a so-called open bit line structure in which each one bit line is connected from both sub-arrays to a sense amplifier is adopted. The same look-up table is registered to multiple banks, successively inputted search keys are sequentially inputted to the multiple banks, and the search operation is carried out in synchronization with the control clocks of different phases.

Abstract: Disclosed is a semiconductor storage apparatus in which two sorts of memories, that is, a volatile memory and a non-volatile memory, are mounted on one chip. Data of a DRAM memory array are saved in a corresponding area of a non-volatile memory before entry to a data retention mode or before power down and data is transferred from the area of the non-volatile memory to the DRAM memory array in exiting from the data retention mode or power up. Normal read/write access is made to the DRAM memory array, while data retention is in an area of the non-volatile memory.

Abstract: A look-up table cascade circuit having N look-up tables connected in cascade for implementing a desired logic function, comprising: N memory cell arrays for storing data of the look-up table in memory cells; N input select circuits for selecting a word line and bit lines to specify memory cells based on an input variable to the look-up table; N output circuits for selectively coupling data in the memory cells selected by the input select circuit to an input/output path and for outputting the data as an output variable of the look-up table; and N?1 connection circuits arranged between each preceding output circuit and each subsequent input select circuit, for receiving an external input variable and the output variable output from each preceding output circuit, and for selectively distributing all or part of an external output variable and the input variable based on connection information.

Abstract: A semiconductor storage device comprising: unit blocks each including memory cells, first row of sense amplifiers on one side of bit lines; second row of sense amplifiers on an other side of the bit lines; first switch means which switches a connection state between the one side of the bit lines and the first row of sense amplifiers; second switch means which switches a connection state between the other side of the bit lines and the second row of sense amplifiers; third switch means arranged in the approximate center of the bit lines in an extending direction thereof to switch a connection state of the bit lines; and refresh control means which divides the unit block into two areas and controls the refresh operation using the switch means and the row of sense amplifiers according to which area a selected word line to be refreshed is in.

Abstract: A memory circuit of the invention comprises N look-up tables for implementing a desired logic function of L inputs/M outputs by partitioning a memory cell array including a plurality of memory cells into portions each corresponding to at least a predetermined number of input/output paths; a decode circuit for selecting one of the N look-up tables by decoding a look-up table select signal and for selecting M memory cells to be accessed included in the selected look-up table by decoding an L-bit logic input signal of the logic function; and a select connect circuit for selectively connecting the input/output paths of the M memory cells to be accessed with an input/output bus for transmitting an M-bit logic output signal of the logic function in response to a decoded result of the decode circuit.

Abstract: The range-specified IP addresses are effectively stored to reduce the number of necessary entries thereby the memory capacity of TCAM is improved. The representative means of the present invention is that: the storage information (entry) and the input information (comparison information or search key) are the common block code such that any bit must be the logical value ‘1’; Match-lines are hierarchically structured and memory cells are arranged at the intersecting points of a plurality of sub-match lines and a plurality of search lines; Further the sub-match lines are connected to main-match lines through the sub-match detectors, respectively and main-match detectors are arranged on the main-match lines.

Abstract: A column circuit that amplifies signals read from a sense amplifier array SAA to local input/output lines LIO in sub-amplifiers SAMP to transfer the amplified signals to main input/output lines MIO is provided. A current control circuit IC that can set one of two kinds of currents according to read enable signals RD1, RD2 is provided in each sub-amplifier SAMP. The read enable signals RD1, RD2 are generated at timings corresponding to the number of cycles in burst read operation under control of the timing controller. Current in the current control circuit IC is set to be large by the RD1 in burst read operation cycle just after activation of a memory bank, while current in the current control circuit IC is set to be small by the RD2 in the next and subsequent burst read cycles. Accordingly, expansion of an operation margin or reduction of power consumption can be realized in a semiconductor device including a semiconductor memory such as a DRAM.

Abstract: A semiconductor circuit of the invention comprises: a memory cell array including a plurality of memory cells formed at intersections between a plurality of word lines and a plurality of bit lines; a plurality of sense amplifiers each for amplifying data of the memory cell connected to a selected word line through the bit line; a plurality of data holding circuits each for holding data transferred from the plurality of sense amplifiers; and a plurality of selectors each for selecting a data holding circuit from a unit group including a predetermined number of the data holding circuits based on logic input data, and for externally connecting one end of the selected data holding circuit.

Abstract: A semiconductor device of the invention comprises: a plurality of unit blocks aligned at least in a bit line extending direction, into which a memory cell array is divided; a plurality of sense amplifiers provided in each of the unit blocks for amplifying data of memory cells through bit lines; a switch circuit capable of switching connection between an input/output port for inputting/outputting data of the unit blocks and the plurality of sense amplifiers; and a redundancy select circuit for controlling the switch circuit so as to maintain connection relation between the input/output port and a predetermined number of the sense amplifiers from which one or more sense amplifiers each corresponding to a defective bit line having a defective memory cell are excluded, in accordance with defect information specifying the defective memory cell in the unit blocks.

Abstract: A self-refresh timer circuit for generating a timer period for controlling self-refresh operation of a semiconductor memory device comprising: a temperature-dependent voltage source for outputting a voltage having a temperature dependency based on a diode characteristic; a control current generating circuit for applying an output voltage of the temperature-dependent voltage source to a temperature detecting device having a diode characteristic and for generating a control current having a magnitude in proportion to a current flowing through the temperature detecting device; and a timer period generating circuit for generating a timer period in inverse proportion to the magnitude of the control current.

Abstract: A semiconductor device of the invention comprises: a memory cell array including memory cells formed at intersections between word lines and bit lines; first and second input/output ports each defined for inputting/outputting data of the memory cell array; sense amplifiers for amplifying data of the memory cells through the bit lines; a first select circuit which is controlled to be on/off by first select control lines extending in an intersecting direction to bit lines and is connected between the sense amplifiers and the first input/output port; a second select circuit which is controlled to be on/off by second select control lines extending along the bit lines and is connected between the sense amplifiers and the second input/output port; and first and second column decoders for selectively activating the first and second select control lines in response to an input column address.