摘要:
A cache-memory control apparatus controls a level-1 (L1) cache and a level-2 (L2) cache having a cache line divided into a plurality of sub-lines for storing data from the L1 cache. The cache-memory control apparatus includes a control-flag adding unit, an L1 cache control unit, and an L2 cache control unit. The control-flag adding unit provides an SP flag to each of the sub-lines. The L1-cache control unit acquires an access virtual address, and, when there is no data at the access virtual address, outputs an L2 cache-access address to the L2-cache control unit. The L2-cache control unit switches the SP flag based on a virtual page number in an L1 index and a physical page number in an L2 index. Based on the SP flag, corresponding one of the sub-lines is written back to the L1 cache.
摘要:
A cache-memory control apparatus controls a level-1 (L1) cache and a level-2 (L2) cache having a cache line divided into a plurality of sub-lines for storing data from the L1 cache. The cache-memory control apparatus includes a control-flag adding unit, an L1 cache control unit, and an L2 cache control unit. The control-flag adding unit provides an SP flag to each of the sub-lines. The L1-cache control unit acquires an access virtual address, and, when there is no data at the access virtual address, outputs an L2 cache-access address to the L2-cache control unit. The L2-cache control unit switches the SP flag based on a virtual page number in an L1 index and a physical page number in an L2 index. Based on the SP flag, corresponding one of the sub-lines is written back to the L1 cache.
摘要:
A second-level cache device stores part of registration information of data for a first-level cache device in a second-level cache-tag unit in association with registration information in a second-level-cache data unit, and stores the registration information of data for the first-level cache device in a first-level cache-tag copying unit. A coherency maintaining processor maintains coherency between the first-level cache device and the second-level cache device based on the information stored in the second-level cache-tag unit and the first-level cache-tag copying unit.
摘要:
A second-level cache device stores part of registration information of data for a first-level cache device in a second-level cache-tag unit in association with registration information in a second-level-cache data unit, and stores the registration information of data for the first-level cache device in a first-level cache-tag copying unit. A coherency maintaining processor maintains coherency between the first-level cache device and the second-level cache device based on the information stored in the second-level cache-tag unit and the first-level cache-tag copying unit.
摘要:
A cache control method controls data sharing conditions in a processor system having multi-level caches that are in an inclusion relationship. The cache control method indexes an upper level cache by a real address and indexes a lower level cache by a virtual address, and prevents a real address that is referred by a plurality of different virtual addresses from being registered a plurality of times within the same cache. A plurality of virtual addresses are registrable within the upper level cache, so as to relax the data sharing conditions.
摘要:
Each of a plurality of memory blocks returns data in different latency in reply to a data request from a request source. The closer a request destination memory block is to the request source, in the shorter latency the data is returned.
摘要:
A cache control method controls data sharing conditions in a processor system having multi-level caches that are in an inclusion relationship. The cache control method indexes an upper level cache by a real address and indexes a lower level cache by a virtual address, and prevents a real address that is referred by a plurality of different virtual addresses from being registered a plurality of times within the same cache. A plurality of virtual addresses are registrable within the upper level cache, so as to relax the data sharing conditions.
摘要:
A cache control device includes, in a secondary cache data unit, a clean area that stores only information that is the same information as that stored in a main storage. Then, the cache control device monitors information on electrical power consumption of the cache control device, determines whether the information on the electrical power consumption is equal to or greater than a predetermined threshold, monitors an activity ratio of a cache memory, and determines whether the activity ratio is equal to or less than a predetermined threshold. Subsequently, if the cache control device determines that the information on the electrical power consumption is equal to or greater than the predetermined threshold or determines that the activity ratio of the secondary cache memory is equal to or less than the predetermined threshold, the cache control device performs control such that the clean area in the secondary cache data unit is degenerated.
摘要:
A power source apparatus of a car is provided with contactors (2) connected to an output-side of a battery (1); a pre-charge circuit (3) made up of a series connected pre-charge resistor (6) and a pre-charge relay (7), which is connected with a contactor (2) to supply auxiliary charge to a capacitor (21) connected to a car-side of the battery (1); and a control circuit (4) to control the contactors (2) and the pre-charge relay (7). The pre-charge resistor (6) is connected in parallel with a contactor (2), and the pre-charge relay (7) is connected in series with that contactor (2). The control circuit (4) switches the pre-charge relay (7) ON to pre-charge the car-side capacitor (21), and then switches the contactor (2) ON to connect the battery (1) to the car-side.
摘要:
There is disclosed a data buffer device that selects and uses buffers to improve persistence of data and uniformity in use frequency of the buffers. The data buffer device includes: a REQ_QUEUE 11 constituted by plural buffers that store data and are given numbers; a mask bit vector 12 that has mask bit patterns to mask the plural buffers, respectively, and sets corresponding one of the mask bit patterns for a released buffer among the plural buffers; a first priority select section 13 that selects a buffer given the smallest number from buffers that are neither masked by the mask bit vector nor used among the plural buffers; a second priority select section 14 that selects a buffer given the smallest number from unused buffers among the plural buffers; and a selector 15 that selects one of the buffer selected by the first priority select section 13 and the buffer selected by the second priority select section 14.