Abstract: High speed memory access and transparent error detection and correction using a single error correcting means are obtained. A host computer writes sector data in one of the first memory and second memory, and next sector data in the other of the first and second memory. Sector data is read out from one of the first memory and second memory to the host computer, and simultaneously, next sector data is read out from the other of the first memory and second memory, and error detection and correction performed in the error correcting means. During a next cycle, the sector data read out from one of the first memory and second memory is outputted to the host computer, and simultaneously, error detection and error correction of the next sector data read out from one of the first computer and second computer is performed in the error correcting means.

Abstract: There is provided a technology to realize high speed data transfer while compatibility of a card type storage device comprising a nonvolatile memory is ensured. Namely, in the card type storage device comprising the nonvolatile memory, a plurality of data terminals are provided and an interface unit is provided with a circuit for determining levels of data terminals. Some or all of the plurality of data terminals are connected with pull-up resistors for pulling up to a power source voltage. When the determination circuit determines that the data terminals connected with the pull-up resistors are in an open condition, the determination circuit switches a bus width (number of bits) of data.

Abstract: A semiconductor memory includes a memory block consisting of a plurality of cells, a write control section, and a read control section. The write control section sets a potential to each of the plurality of cells in such a manner that the potential corresponds to a level indicated by a bit data string obtained by arranging pieces of bit data which are stored in buffers A and B and which are to be stored in the cell in the order of the buffer A and the buffer B. The read control section has a discriminator corresponding to each of the plurality of cells. The discriminator sets a threshold voltage to a potential level that corresponds to a number of discriminating operations to be performed with respect to a corresponding cell and a result of a discriminating operation already performed with respect to the cell.

Abstract: A database operation processor includes a self-join detector for detecting if a self-join operation is included in a query statement for a table in a database and generating a self-join operation expression, a join key classifier for classifying a join key included in a join condition in the operation expression into an equi-join key or a non equi-join key based on the generated self-join operation expression, and a self-join operation executor for sorting records stored in the table by the equi-join key, inputting in the sorted table, executing the generated self-join operation expression, and producing a result for the query statement.

Abstract: A semiconductor storage device that determines the cause of an error at the time of the error correction of data read out from a non-volatile semiconductor memory, on the basis of a previously recorded error correction count, and selects a data refresh processing or a substitute processing to perform. When the error is detected, the corrected data is rewritten back for preventing reoccurrence of error due to accidental cause. If it is determined that the reoccurrence frequency of the error is high and the error is due to degradation of the storage medium, based on the error correction count, the substitute processing is performed.

Abstract: In a card storage device containing a non-volatile memory and a buffer memory, the buffer memory includes a plurality of banks. Data is transferred sequentially from a host CPU to the banks of the buffer memory, data is transferred to the non-volatile memory from a bank that becomes full, a write operation is started when one unit of data to be written into the non-volatile memory at a time has been transferred and, without waiting for the data to be written, the next write data is transferred from the host CPU to a bank from which write data has been transferred.

Abstract: A semiconductor memory includes a memory block consisting of a plurality of cells, a write control section, and a read control section. The write control section sets a potential to each of the plurality of cells in such a manner that the potential corresponds to a level indicated by a bit data string obtained by arranging pieces of bit data which are stored in buffers A and B and which are to be stored in the cell in the order of the buffer A and the buffer B. The read control section has a discriminator corresponding to each of the plurality of cells. The discriminator sets a threshold voltage to a potential level that corresponds to a number of discriminating operations to be performed with respect to a corresponding cell and a result of a discriminating operation already performed with respect to the cell.

Abstract: In response to a read command received by a system interface unit for accessing a plurality of blocks of data stored in said non-volatile semiconductor memory, a controller carries out selective read operations of blocks of data to two memories from the non-volatile semiconductor memory. The controller also carries out parallel operations of data transferring a first block of data, which has already been subjected to error detection and error correction operations by an error correction unit, from one of the two memories to a host system via said system interface unit and of data transferring of a second block of data to be subjected to the error detection and error correction operation, from said non-volatile semiconductor memory to the other of the two memories.

Abstract: The present invention provides a memory card in which stored information is not lost undesirably even when an operation power source is shut down during an erasing/writing process. A nonvolatile memory has an erase table in which a free-space information flag is associated with each physical address of a memory area and an address translation table in which a physical address of a memory area is associated with each logical address. The free-space information flag indicates whether a corresponding memory area is permitted to be erased or not. A control circuit determines a memory area to which rewrite data is to be written by referring to the free-space information flag of the erase table, reflects the physical address and the logical address of the memory area to which the data is written into the address translation table, and updates the free-space information flag of the erase table.

Abstract: Disclosed is a nonvolatile memory apparatus in which a nonvolatile memory and a controller are mounted and which realizes improved performance of read/write speeds and improved resistance to a retention error. A nonvolatile memory can store information of two bits or more, and can perform a first reading operation of outputting information read from a nonvolatile memory cell as 1-bit information and a second reading operation of outputting the read information as 2-bit information. A controller performs the first reading operation to read first information from the nonvolatile memory and performs the second reading operation to read second information. The reading speed of the first reading operation is faster than that of the second reading operation.

Abstract: High-speed memory access and transparent error detection and correction using a single error correcting means are obtained and processed by an external storage device of a host computer when sector data having an arbitrary byte width are accessed continuously according to a size of a sector unit. Consequently, the host computer always reads sector data, and at the same time, error detection and the error correction for a next sector data are simultaneously performed, thereby greatly reducing the time required for error detection and error correction, and high speed memory access can be obtained.

Abstract: The memory device has an electrically rewritable nonvolatile memory used as a storage medium. To promote even deterioration throughout the memory, the erasing time and writing time are measured, the influence of scatter of cells in the memory are eliminated on the basis of the resultant measurement values and a degree of deterioration is determined with a high accuracy, whereby a memory device of a high reliability and high efficiency is realized. In order to rewrite the nonvolatile memory, therefore, the memory measures erasing time and writing time, compares erasing time with stored reference time, compares the writing time from the comparison results, and determines the degree of deterioration from the correction results. Accordingly, control is possible such that, successively, the more heavily deteriorated part of the memory is used less frequently while the less deteriorated part is used more frequently.

Abstract: In response to a read command received by a system interface unit for accessing a plurality of blocks of data stored in said non-volatile semiconductor memory, a controller carries out selective read operations of blocks of data to two memories from the non-volatile semiconductor memory. The controller also carries out parallel operations of data transferring a first block of data, which has already been subjected to error detection and error correction operations by an error correction unit, from one of the two memories to a host system via said system interface unit and of data transferring of a second block of data to be subjected to the error detection and error correction operation, from said non-volatile semiconductor memory to the other of the two memories.

Abstract: A semiconductor memory includes a memory block consisting of a plurality of cells, a write control section, and a read control section. The write control section sets a potential to each of the plurality of cells in such a manner that the potential corresponds to a level indicated by a bit data string obtained by arranging pieces of bit data which are stored in buffers A and B and which are to be stored in the cell in the order of the buffer A and the buffer B. The read control section has a discriminator corresponding to each of the plurality of cells. The discriminator sets a threshold voltage to a potential level that corresponds to a number of discriminating operations to be performed with respect to a corresponding cell and a result of a discriminating operation already performed with respect to the cell.

Abstract: In the conventional nonvolatile memory, it is not possible to determine the cause of the error is accidental or due to the degradation when the error is detect at the time of data read. Therefore, unnecessary substitute processing is performed, resulting in the exhaustion of the substitute area to shorten the life of the storage device.

Abstract: A structured document type determination system is provided with a feature value extraction unit for extracting a value of each of a plurality of features included in a feature list which is disposed in advance from each of a plurality of structured documents and a determination rule creating unit for creating a determination rule from extracted feature values by using a data mining tool. The structured document type determination system makes an evaluation of the determination rule by comparing results of determining the types of structured documents according to the determination rule and teacher data, and repeatedly delivers a tuning parameter to the data mining tool so as to create a plurality of determination rules and to derive an optimum determination rule.

Abstract: In a memory including a flash memory, the life of the memory is prevented from being decreased due to the high frequency of rewrite operations of data to a specific area. When the erasure frequency of a block 301, storing four sectors of data, is high, each sector of block 301 is transferred to different blocks 302-305 to avoid deterioration of the data of block 301 due to the high frequency of rewriting.

Abstract: An information processing apparatus is provided which is capable of carrying out the higher memory access. The information processing apparatus includes a memory unit of a synchronous DRAM device which serves to output data synchronously with the supplied clock signal, and a control unit for controlling the access to the memory unit in accordance with an instruction issued from a CPU. The clock signal which is to be supplied to the memory unit is outputted from the control unit. The clock signal which has been outputted from the control unit is supplied to the memory unit and also is pulled back to the control unit. The control unit fetches therein the data, which has been outputted from the storage unit, at the timing which is determined on the basis of the pulled back clock signal. As a result, the control unit reduces the difference between a delay of the data which is outputted from the control unit and a delay of the clock signal which is used to determine the timing at which the data is fetched therein.

Abstract: In response to a read command received by a system interface unit for accessing a plurality of blocks of data stored in said non-volatile semiconductor memory, a controller carries out selective read operations of blocks of data to two memories from the non-volatile semiconductor memory. The controller also carries out parallel operations of data transferring a first block of data, which has already been subjected to error detection and error correction operations by an error correction unit, from one of the two memories to a host system via said system interface unit and of data transferring of a second block of data to be subjected to the error detection and error correction operation, from said non-volatile semiconductor memory to the other of the two memories.

Abstract: A semiconductor storage device that determines the cause of an error at the time of the error correction of data read out from a non-volatile semiconductor memory, on the basis of a previously recorded error correction count, and selects a data refresh processing or a substitute processing to perform. When the error is detected, the corrected data is rewritten back for preventing reoccurrence of error due to accidental cause. If it is determined that the reoccurrence frequency of the error is high and the error is due to degradation of the storage medium, based on the error correction count, the substitute processing is performed.