49 results about "Dirty bit" patented technology

In a tile-based graphics processing system, when an overlay image is to be rendered onto an existing image, the existing tile data for the existing image from the frame buffer in the main memory is pre-loaded into the local colour buffer of the graphics processor (step 41). The overlay content is then rendered and used to modify the tile data stored in the colour buffer (step 44). When the data for a given sampling position stored in the tile buffer is modified as a result of the overlay image, a corresponding dirty bit for the tile region that the sampling position falls within is set (step 45). Then, when all the rendering for the tile has been completed, the dirty bits are examined to determine which regions of the tile have been modified (step 46). The modified tile regions are written back to the output image in the frame buffer in the main memory (step 47), but any regions whose dirty bits have not been set are not written back to the frame buffer in the main memory.

A memory interface controls read and write accesses to a memory device. The memory device includes a level-one cache, level-two cache and storage cell array. The memory interface includes a data request processor (DRP), a memory control processor (MCP) and a block cleansing unit (BCU). The MCP controls transfers between the storage cell array, the level-two cache and the level-one cache. In response to a read request with associated read clear indication, the DRP controls a read from a level-one cache block, updates bits in a corresponding dirty tag, and sets a mode indicator of the dirty tag to a the read clear mode. The modified dirty tag bits and mode indicator are signals to the BCU that the level-one cache block requires a source clear operation. The BCU commands the transfer of data from a color fill block in the level-one cache to the level-two cache.

Page table data for each page within a memory address space includes a write permission flag and a dirty-bit-modifier flag. The write permission flag is initialised to a value indicating that write access is not permitted. When a write access occurs, then the dirty-bit-modifier flag indicates whether or not the action of the write permission flag may be overridden. If the action of the write permission flag may be overridden, then the write access is permitted and the write permission flag is changed to indicate that write access is thereafter permitted. A page for which the write permission flag indicates that writes are permitted is a dirty page.

A semiconductor device is designed to hide refresh operations even when the data width of a cache line differs from that of the external data bus in a memory that uses a cache memory and a DRAM with a plurality of banks. The semiconductor device includes a plurality of memory banks BANK0 to BANK127, each having a plurality of memory cells, as well as a cache memory CACHEMEM used to retain information read from the plurality of memory banks. The cache memory CACHEMEM includes a plurality of entries, each having a data memory DATAMEM and a tag memory TAGMEM. The data memory DATAMEM has a plurality of sub lines DATA0 to DATA3 and the tag memory TAGMEM has a plurality of valid bits V0 to V3 and a plurality of dirty bits D0 to D3.

To provide a semiconductor device with less power consumption. In a semiconductor device including a CPU, the frequency of access to a cache memory is monitored. In the case where the access frequency is uniform, supply of a power supply voltage to the CPU is stopped. In the case where the access frequency is not uniform, stop of supplying the power supply voltage is performed on memories with a time interval, and eventually, supply of the power supply voltage to the CPU is stopped. Further, write back processing is efficiently performed in accordance with determination of a dirty bit, so that power consumption of the semiconductor device can be further achieved.

A cache controller in a computer system is configured to manage a cache such that the use of bus bandwidth is reduced. The cache controller receives commands from a processor. In response, a cache mapping maintaining information for each block in the cache is modified. The cache mapping may include an address, a dirty bit, a zero bit, and a priority for each cache block. The address indicates an address in main memory for which the cache block caches data. The dirty bit indicates whether the data in the cache block is consistent with data in main memory at the address. The zero bit indicates whether data at the address should be read as a default value, and the priority specifies a priority for evicting the cache block. By manipulating this mapping information, commands such as move, copy swap, zero, deprioritize and deactivate may be implemented.

A digital system and method of operation is provided in which the digital system has at least one processor, with an associated multi-segment cache memory circuit (506(n). Validity circuitry (VI) is connected to the memory circuit and is operable to indicate if each segment of the plurality of segments holds valid data. Dirty bit circuitry (DI) is connected to the memory circuit for indicating if data within the cache is incoherent with a secondary back-up memory. DMA circuitry can transfer (1652) blocks of data/instructions (1660) between the cache and a secondary memory (1602). A transfer mode circuit (1681) controls how DMA operations are affected by the dirty bits. If the transfer mode circuit is in a first mode, a DMA operation transfers only segments (1661) indicated as dirty (1685). If the transfer mode circuit is in a second mode, a DMA operation transfers and entire block of data (1660) without regard to dirty indicators (1686). DMA transfers from the cache to secondary memory are thereby configured to be responsive to the dirty bits. A dirty bit mode circuit (1680) controls how DMA transfers affect the dirty bits. When the mode circuit is in a first mode, DMA transfers set the affected dirty bits to a clean state. When the dirty bit mode circuitry is in an alternate mode, DMA transfers set the affected dirty bits to a dirty state. A cache clean operation will thus copy data provided by a DMA transfer and indicated as dirty into backup secondary memory.

A media player is presented that scans the media files stored on an external memory card in order to update the internal database of the player. Media manager software on a personal computer sets a dirty bit in the internal memory of the media player whenever the media files on the external memory card are altered. The media player checks the dirty bit on start up or when the memory card is inserted. If the dirty bit is set, the media player scans the media files on the memory card, updates its database, then clears the dirty bit. If the dirty bit is not set, the media player does not scan the memory card. The dirty bit is associated in the internal memory with an identifier for the memory card, allowing the use of multiple memory cards.

The invention discloses an NOR-FLASH data storage method, a computer device and a storage medium. The NOR-FLASH is divided into a control region and a user region, and the method comprises the following steps of applying for writing the sector data into an idle mapping sector from the user region according to a dirty bitmap; updating the dirty bitmap, a recovery bitmap and a dynamic mapping table;writing the mapping relation between a logical sector number and a mapping sector number into a log area, wherein if the log area is full before writing, the dynamic mapping table is backed up to thestatic mapping table, and the log area is erased. According to the NOR-FLASH data storage method, the computer device and the storage medium provided by the invention, by setting the dirty bitmap, the recovery bitmap and the dynamic mapping table, the sector of the NOR-FLASH is planned and managed, the limited abrasion uniformity of the sector in the NOR-FLASH is realized, and the service life ofthe NOR-FLASH can be prolonged; by setting the log records to record the data writing process and utilizing the static mapping table to back up the data of the dynamic mapping table, the data cannotbe lost when power failure occurs during data writing.

Disclosed are a method and apparatus for controlling a cache memory in an electronic device. The apparatus includes a cache memory having cache lines, each of which includes tag information and at least two sub-lines. Each of the at least two sub-lines including a valid bit and a dirty bit. A control unit may analyze a valid bit of a sub-line corresponding to an address tag of data when a request for writing the data is sensed, determine based on activation or deactivation of the valid bit whether a cache hit or a cache miss occurs, and perform a control operation for allocating a sub-line according to a size of the requested data and write the data when the cache hit occurs.

A method that allows use of a memory page dirty bit by a number of modules.

Expression-based data may comprise data that is processed by a validation expression for example. After a validation expression is created it may then be performed with respect to one or more data values or data records. A validation expression returns a Boolean result that signifies a success or failure result. A validation expression can define complex intra-record tests and inter-record tests with unlimited complexity. In order to improve processing of validations, the system uses virtual data known as calculation fields. Calculation fields are stored in memory at runtime and not in a database thereby eliminating the necessity of selecting and updating records in the database. A dirty bit identifying fields and attributes that need to be calculated based on a dependent data may be used to defer calculation to a later time when the calculation field is displayed or a sort operation occurs for example.

The invention discloses a hybrid memory page migration method for an image processing type load, and relates to a hybrid memory page migration method. The invention aims to solve the problems of shortservice life and damaged performance of the existing hybrid memory. And at the moment t, when a write operation occurs in the PCM page and the number of times of the write operation of the page is greater than or equal to n and the dirty bit of the page is 1, searching for a replacement page in a DRAM or a DRAM cache, starting migration, and requesting a counter to add 1. Requesting the counter to restart counting every integer multiple of the memory reference distance, and setting all dirty bits of the page in the PCM cache to be zero. And then enabling t to be equal to t + 1, and executingthe above steps again. The method is applied to the field of hybrid memory page migration of image processing type loads.

The invention relates to a hot writing page prediction method based on memory access, in particular to a hot writing page prediction method based on memory access. The invention aims to solve the problems of short service life and damaged performance of the existing hybrid memory. According to the invention, the PCM cache and the DRAM cache are set; wherein the PCM access memory is used for storing a written PCM page; wherein the DRAM cache is used for storing an accessed DRAM page and time t, and when a write operation occurs in the PCM page, the page is in the PCM cache and the dirty position of the page is 1, a replacement page is searched in the DRAM or the DRAM cache, migration is started, and a counter is requested to add 1. Requesting the counter to restart counting every integer multiple of the memory reference distance, and setting all dirty bits of the page in the PCM cache to be zero. Then, t is made to be equal to t + 1, and the steps are executed again; The method is applied to the field of page write heat prediction.