Abstract: An information recording medium contains a semiconductor memory as a storage device for storing data and having plural areas to be managed by mutually independent file systems, an area information storage for storing information about size and position of each area of the semiconductor memory, a host interface for receiving a command for setting each area size of the semiconductor memory from an accessing device, and an area size setter for setting the size and position of each area of the semiconductor memory. The area size setter sets the area size of each area in the semiconductor memory based on the specified setting condition according to the command received from the accessing device.

Abstract: A memory controller (220) that controls the writing of data into or the reading of data from a non-volatile memory (230) includes a host interface unit (210) and a host information management unit (223). The host interface unit (210) receives an application ID identifying an application used when recording user data into the non-volatile memory (230) and a device ID identifying an external device (100) that uses the stated application. The host information management unit (223) records a host information table indicating a correspondence relationship between the application ID and the device ID into the non-volatile memory. The memory controller (220) can thus easily determine by what data processing device the data stored in a non-volatile storage device (200) attachable to/removable from the external device (100) has been updated.

Abstract: A semiconductor recording medium holds an open flag showing presence or absence of consistency between content data stored in a data storage section and file system management information, in a system region not directly accessible from a host device. Upon receipt of a write request or erase request to the data storage section from the host device, the semiconductor recording medium automatically updates the open flag to “ON” (value showing possibility of inconsistency). When actual consistency is verified, the host device requests the recording medium to set the open flag to “OFF” (value showing presence of consistency). When mounting, the host device refers to the open flag with a special command to judge necessity for error check process.

Abstract: In a file system such as an FAT file system, clusters are linked only in the forward direction. To perform seeks to clusters in the reverse direction, links need to be followed from the beginning side of the file data in every seeking operation. When a large amount of data is subjected to such reverse seeking, the overhead will be particularly large. A memory controller (101) for controlling data writing or reading to or from an information recording medium includes a control unit (105) that detects continuity of data in an address space of a file system managing data that is recorded into the information recording medium and a data-continuity management unit (103) that stores information about the continuity of the data as data-continuity information.

Abstract: A predetermined number of erasable blocks positioned at a start of a volume area in a semiconductor memory card are provided so as to include volume management information. A user area following the volume management information includes a plurality of clusters. A data length NOM of an area from a master boot record & partition table sector to a partition boot sector is determined so that the plurality of clusters in the user area are not arranged so as to straddle erasable block boundaries. Since cluster boundaries and erasable block boundaries in the user area are aligned, there is no need to perform wasteful processing in which two erasable blocks are erased to rewrite one cluster.

Abstract: A file system (105) and a nonvolatile memory device (101) notify each other of the cluster size and the logic block size respectively in advance. In writing, the file system notifies the nonvolatile memory device of data as to which cluster of the file system can be discarded in the logical block of the nonvolatile memory device. With this, the nonvolatile memory device can avoid the copy of data at the writing, so that the nonvolatile memory device is not required to continuously keep data of an unnecessary file.

Abstract: The present invention relates to prevention of erroneous connection in an optical network and, in particular, it provides an optical communication node having route switching function as well as an optical network system using the same in a wavelength division multiplex (WDM) network system. There is provided an optical communication node that is connected to a specific optical path in an optical network, the optical communication node having: an external network that is placed thereunder; and an interruption part for interrupting connection between the optical network and the external network, wherein the interruption part interrupts the connection until a sequence of changing a route is completed when the route setting of the optical path is changed.

Abstract: During initial start-up of an optical communication system, an ASE reference span loss is calculated based on transmitting power and received power of ASE light generated by an optical amplifier, and an OSC reference span loss is calculated based on the transmitting power and the received power of OSC light. During normal operation of the optical communication system, a span loss is calculated using the OSC light, and an amount of change in the span loss representing a difference between the span loss and the OSC reference span loss is calculated. A current span loss between a transmitting station and a receiving station is calculated by adding the amount of change in the span loss to the ASE reference span loss.

Abstract: An identification apparatus for identifying an optical passive device product. The apparatus includes an optical input output monitor section for monitoring an optical input and an optical output of the optical passive device product respectively; a loss calculation section for calculating a loss in the optical passive device product based on a monitoring result of the optical input output monitor section; and a product identification section in which product information indicating a correspondence between a loss characteristic and a product has been stored in advance, and which identifies the optical passive device product by comparing the stored product information and the loss calculated by the loss calculation section.

Abstract: A predetermined number of erasable blocks positioned at a start of a volume area in a semiconductor memory card are provided so as to include volume management information. A user area following the volume management information includes a plurality of clusters. A data length NOM of an area from a master boot record & partition table sector to a partition boot sector is determined so that the plurality of clusters in the user area are not arranged so as to straddle erasable block boundaries. Since cluster boundaries and erasable block boundaries in the user area are aligned, there is no need to perform wasteful processing in which two erasable blocks are erased to rewrite one cluster.

Abstract: Without corresponding to different address spaces between an access device (100) and a nonvolatile memory device (200), the access device (100) designates a file ID to manage a data storing state only in a physical address space in the nonvolatile memory device (200). The access device (100) sends the nonvolatile memory device (200) a transfer rate through a transfer rate transmitting unit (121). A filling-up rate calculating unit (251) calculates a filling-up rate of a physical block corresponding to an assurance speed required by the access device (100). A remaining amount corresponding to the transfer rate is sought by using the calculated rate and is transmitted to a remaining amount receiving unit (122) of the access device (100).

Abstract: An development environment of a high security level is provided for a key-installed system. Development of a program for a system having an LSI device which includes a secure memory is performed by providing another LSI device having the same structure and setting the provided LSI device to a development mode which is different from a product operation mode. Alternatively, the provided LSI device is set to an administrator mode to perform development and encryption of a key-generation program. The LSI device is set to a key-generation mode to execute the encrypted key-generation program, thereby generating various keys.

Abstract: A data processing apparatus is capable of playing back contents stored in a specified area in a recording medium. The recording medium stores content data and management information for managing the content data. When playing back a content which is managed by the management information on the recording medium but of which entity data is not present in the specified area of the recording medium, the data processing apparatus, searches, for the content, the other area of the recording medium with a search section. When the corresponding content is found, the link information selling section sets the link information (symbolic link, shortcut, etc.) on the recording medium so that the content can be accessed with the management information.

Abstract: A host information memory is provided in a semiconductor memory card and a data write start address and a data size supplied by an access unit are stored. A free physical area generation section determines whether or not to perform erasing of an invalid block of a nonvolatile memory when writing of data based on the data write start address and data size, and determines the number of blocks to be erased. When erasing, writing of data and erasing of invalid blocks are simultaneously performed with respect to different memory chips. Erase process of data, herewith, can be optimized and high speed access from the access unit to a semiconductor memory card can be realized.

Abstract: When an access device accesses a nonvolatile memory device, the nonvolatile memory device or the access device detects or calculates a temperature T of the nonvolatile memory device. A temperature-adaptive control part of the nonvolatile memory device controls an access rate to a nonvolatile memory on the basis of the temperature T. Accordingly, the control part controls the rate so that the temperature T of the nonvolatile memory devices cannot exceed a limit temperature Trisk. In this manner, a nonvolatile memory system can eliminate a risk of a burn when ejecting the semiconductor memory device and can read and write data at a high speed.

Abstract: A region management method for an information recording medium capable of maintaining data interchangeability among devices and preventing malfunction when one information recording medium shared among devices different in type or number of file systems that can be interpreted by devices is provided. A recording region of the information recording medium is divided into a plurality of regions, and region information such as position and size of each region is held in the information recording medium. Different file systems are constructed in individual data recording regions. In response to a command from an information processing apparatus, accessible regions by the information processing apparatus are changed over by, for example, referring to validity flag information that indicates a presently valid region.

Abstract: A nonvolatile memory device reads and writes file data according to a file ID designated by an access device. The nonvolatile memory device includes a capacity parameter decision part 260 which generates a capacitance parameter related to a usable capacity of a nonvolatile memory 210. Even if a defective region of the nonvolatile memory is gradually increased as the use is continued, a capacity parameter decision part 161 reduces a normal region in accordance with increase of the defective region. The capacity parameter notification part notifies the reduced capacity parameter to the access device. Based on the notified capacity parameter, the access device manages the total size of all the files to be read and written.

Abstract: A file to be read or written is designated and accessed from an access device side to a nonvolatile memory device. In an initialization after start-up of the power source, an empty capacity detector detects empty capacity parameters of a nonvolatile memory with dividing the memory into a plurality of regions. An empty capacity parameter notification part notifies the access device of the empty capacity parameters in a stepwise fashion whenever the empty capacity detector detects an empty capacity. With this, at the time when the empty capacity becomes not less than a capacity required to write file data, the data can be written to the nonvolatile memory without waiting for completion of the initialization, resulting in improvement of a response in the recording.

Abstract: An access device 100 includes an access speed information part 112 for informing an access speed required for data recording by the access device 100 to a nonvolatile memory device 200. The nonvolatile memory device includes an access condition determination part 212 for determining an access condition required for meeting the informed access speed and an access area determination unit 213 for determining an access area according to the determined access condition. The access device 100 informs the required access speed to the nonvolatile memory device 200 in advance so that the access condition determination part 212 and the access area determination part 213 in the nonvolatile memory device 200 realize data recording which meets the access speed informed in advance upon the data recording. Thus, it is possible to access all the nonvolatile memory devices at a desired speed regardless of difference in characteristics of the recording speed of each of the nonvolatile memory devices.

Abstract: A nonvolatile memory device has a file system manager and manages the file system of a file to be recorded. The nonvolatile memory device measures time by obtaining time information from outside in each writing file data or based on time information preliminarily obtained. At the time of writing file data, management information of the file system is configured based on the time information at the time. Thus, the time information can be stored in a file entry table, and the time information can be used as file management information. The nonvolatile memory system with high user's convenience can be provided.