摘要:
The present invention relates to a multithread processor. In the multithread processor, when a cache miss occurs on a request related to an instruction in, of a plurality of caches arranged hierarchically, a cache at the lowest place in the hierarchy, with respect to the request suffering the cache miss, a cache control unit notifies an instruction identifier and a thread identifier, which are related to the instruction, to a multithread control unit. When a cache miss occurs on an instruction to be next completed, the multithread control unit makes the switching between threads on the basis of the instruction identifier and thread identifier notified from the cache control unit. This enables effective thread switching, thus enhancing the processing speed.
摘要:
The present invention relates to a multithread processor. In the multithread processor, when a cache miss occurs on a request related to an instruction in, of a plurality of caches arranged hierarchically, a cache at the lowest place in the hierarchy, with respect to the request suffering the cache miss, a cache control unit notifies an instruction identifier and a thread identifier, which are related to the instruction, to a multithread control unit. When a cache miss occurs on an instruction to be next completed, the multithread control unit makes the switching between threads on the basis of the instruction identifier and thread identifier notified from the cache control unit. This enables effective thread switching, thus enhancing the processing speed.
摘要:
An apparatus for efficient parallel executing instruction avoiding the usage of cross bypasses, the apparatus including an instruction buffer for storing instructions, of decoders for decoding, in parallel, the instructions which simultaneously issue from the instruction buffer, executing units for executing the instructions decoded in the decoders, and an instruction-issuing controlling means for controlling the issuing of the instructions in such a way that, when the instructions are executed, one of the plural executing units executes instructions more frequently than the rest of the plural executing units. The apparatus is preferably incorporated in an information processor to superscalar or out-of-order instruction execution.
摘要:
A data processing system is provided. The data processing system includes a plurality of processors, a cache memory shared by the plurality of processors, in which memory a cache line is divided into a plurality of partial writable regions. The plurality of processors are given exclusive access rights to the partial writable region waits.
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 data processing system is provided. The data processing system includes a plurality of processors, a cache memory shared by the plurality of processors, in which memory a cache line is divided into a plurality of partial writable regions. The plurality of processors are given exclusive access rights to the partial writable region waits.
摘要:
A cache memory control unit that controls a cache memory comprises: a PF-PORT 22 and MI-PORT 21 that receive a prefetch request and demand fetch request issued from a primary cache; and a processing pipeline 27 that performs swap processing when the MI-PORT 21 receives a demand fetch request designating the same memory address as that designated by a prefetch request that has already been received by the PF-PORT 22, the swap processing being performed so that an MIB 28 that has been ensured for replying the prefetch request is used for a reply to the demand fetch request following the prefetch request.
摘要:
A transmitting side device (10) and a receiving side device (20) are connected to each other via a bus (30) comprising TAG bits (31), data bits (32) and error detection/correction ECC bits (33). The transmitting side device (10) uses a redundant bit inversion circuit (14) to invert different bits of the ECC bits (33) corresponding to trigger signals (41 & 42). In the receiving side device (20), a determination circuit (24), which has received an error report signal (26) from an error detection/correction circuit (22), determines, from the position of an error bit in the ECC bits (33), which one of the trigger signals (41 & 42) has been transmitted from the transmitting side device (10).
摘要:
To reduce the number of bits required for LRU control when the number of target entries is large, and achieve complete LRU control. Each time an entry is used, an ID of the used entry is stored to configure LRU information so that storage data 0 stored in the leftmost position indicates an ID of an entry with the oldest last use time (that is, LRU entry), for example as shown in FIG. 1(1). An LRU control apparatus according to a first embodiment of the present invention refers to the LRU information, and selects an entry corresponding to the storage data 0 (for example, entry 1) from the LRU information as a candidate for the LRU control, based on the storage data 0 as the ID of the entry with the oldest last use time.
摘要:
A cache controller that writes data to a cache memory, includes a first buffer unit that retains data flowing in from outside to be written to the cache memory, a second buffer unit that retains a data piece to be currently written to the cache memory, among pieces of the data retained in the first buffer unit, and a write controlling unit that controls writing of the data piece retained in the second buffer unit to the cache memory.