摘要:
A memory management and protection system for realizing a high speed execution and a proper and flexible memory access control for multiple programs sharing an identical logical address space. In the system, the memory access is permitted according to a segment identifier identifying a segment in the logical address space, and a memory protection information for a region in each segment including a target right permission to indicate assigned rights to make a memory access from the region to each of the segments, and an execution permission to indicate a type of the memory access permitted by the right permission. Alternatively, a memory access can be permitted by using an access control list to be attached to each address table entry, which stores a plurality of program numbers identifying programs which are permitted to make accesses to the logical address stored in each address table entry, among which one that matches with the current program number is to be searched. Also, it is preferable to allocate a plurality of programs within a limit of available memory protection capacity to an identical logical address space, without any overlap between adjacently allocated address regions.
摘要:
A memory management and protection system for realizing a high speed execution and a proper and flexible memory access control for multiple programs sharing an identical logical address space. In the system, the memory access is permitted according to a segment identifier identifying a segment in the logical address space, and a memory protection information for a region in each segment including a target right permission to indicate assigned rights to make a memory access from the region to each of the segments, and an execution permission to indicate a type of the memory access permitted by the right permission. Alternatively, a memory access can be permitted by using an access control list to be attached to each address table entry, which stores a plurality of program numbers identifying programs which are permitted to make accesses to the logical address stored in each address table entry, among which one that matches with the current program number is to be searched. Also, it is preferable to allocate a plurality of programs within a limit of available memory protection capacity to an identical logical address space, without any overlap between adjacently allocated address regions.
摘要:
A multiprocessor system including a master processor, a plurality of processor elements, each of which is provided with a local memory, the processor elements being controlled in accordance with commands from the foregoing master processor, and a global memory shared by the plurality of processor elements is disclosed. The processor elements are provided with a command pooling buffer capable of accumulating a plurality of commands, respectively. DMA controllers are also provided with a command pooling buffer capable of accumulating a plurality of commands, respectively. The master processor persistently issues a plurality of commands to the DMA controller and each processor element. A counter array manages the number of the issued commands which have received no response. When the responses are returned with respect to all issued commands, the counter array notifies the master processor of this.
摘要:
According to an embodiment, a memory system includes semiconductor memories each having a plurality of blocks; a first table; a receiving unit; a generating unit; a second table; and a writing unit. The first table includes a plurality of memory areas each associated with each block and in each of which defect information is stored. The generating unit generates a set of blocks by selecting one block to which data are to be written in each semiconductor memory based on an index number indicating one of a plurality of rows in the first table and the first table. In the second table, an index number and a channel number are stored for each logical block address in association with one another. When a write command is received by the receiving unit, the writing unit writes data to a block associated with a selected channel number among blocks constituting the set.
摘要:
A semiconductor memory device includes: plural semiconductor memory chips to store information depending on an amount of accumulated charge; plural parameter storage units provided in correspondence with the semiconductor memory chips, each parameter to store therein a parameter that defines an electrical characteristic of a signal used for writing information into or reading information from a corresponding one of the semiconductor memory chips; an error correction encoding unit configured to generate a first correction code capable of correcting an error in the information stored in a number of semiconductor memory chips no greater than a predetermined number out of the semiconductor memory chips, from the information stored in the semiconductor memory chips; and a parameter processing unit configured to change the parameters respectively corresponding to the number of semiconductor memory chips no greater than the predetermined number, and write the parameters changed into the parameter storage units, respectively.
摘要:
A volatile management memory stores management information for managing a use state of a storage medium. A management information storing unit divides the management information into plural division pieces and individually stores them in the storage medium. A main controller receives a command from a host device while the division pieces are being stored, performs data processing for the storage medium in response to the command between each division piece is stored, updates the management information divided into the division pieces according to the data processing content, and creates a log representing an update content of the management information. A log storing unit stores the log in the storage medium. A restoring unit reads the division pieces stored in the storage medium to the management memory as the management information, updates the management information according to the log stored in the storage medium, and restores the updated management information.
摘要:
The semiconductor device includes a controller and a plurality of dynamically reconfigurable circuits connected to one another in series below the controller to perform operations in the manner of a pipeline. The controller inputs data and reconfiguration information to the first one of the dynamically reconfigurable circuits. Each of the dynamically reconfigurable circuits includes a processing unit that performs a data computation, an updating unit that updates the reconfiguration information, and a repetition controlling unit that determines whether to repeat the computation and controls the data and the reconfiguration information.
摘要:
According to one embodiment, a controller controls writing into and reading from a storage apparatus that includes a first data-storage unit and a second data-storage unit. The second data-storage unit stores user data and parity data of the user data. The first data-storage unit stores the parity data. The controller includes a parity updating unit and a parity writing unit. When parity data is updated, the parity updating unit writes the updated parity data into the first data-storage unit. When a certain requirement is satisfied, the parity writing unit reads the parity data written in the first data-storage unit, and writes the parity data thus read into the second data-storage unit.
摘要:
As a semiconductor storage device that can efficiently perform a refresh operation, provided is a semiconductor storage device comprising a non-volatile semiconductor memory storing data in blocks, the block being a unit of data erasing, and a controlling unit monitoring an error count of data stored in a monitored block selected from the blocks and refreshing data in the monitored block in which the error count is equal to or larger than a threshold value.
摘要:
When data in one semiconductor memory device is corrupted during a padding process by a padding unit and the data cannot be recovered even by using an error correcting code for correcting a data error, a storage control device issues a data recovery request to a data recovery device. The data recovery device reads the data from other semiconductor memory device in response to the data recovery request to recover the data, and returns a recovery result to the padding unit in the storage control device to perform the padding process.