A memory cell mat is divided into a plurality of entries, and an arithmetic logic unit is arranged corresponding to each entry. Between the entries and the corresponding arithmetic logic units, arithmetic/logic operation is executed in bit-serial and entry-parallel manner. Where parallel operation is not very effective, data is transferred in entry-serial and bit-parallel manner to a group of processors provided at a lower portion of the memory mat. In this manner, a large amount of data can be ...

A system and method to reduce the time for system initializations is disclosed. In accordance with the invention, data accessed during a system initialization is loaded into a non-volatile cache and is pinned to prevent eviction. By pinning data into the cache, the data required for system initialization is pre-loaded into the cache on a system reboot, thereby eliminating the need to access a disk.

A system may include multiple nodes, and each node may include a processing subsystem and an interface that are coupled by an address network and a data network. The nodes' interfaces may communicate over an inter-node network. Each processing subsystem may transition an access right to a coherency unit in response to a data packet on the data network and transition an ownership responsibility for the coherency unit in response to an address packet on the address network such that the access rig...

A method of improving memory latency associated with a read-type operation in a multiprocessor computer system is disclosed. After a value (data or instruction) is loaded from system memory into a cache, the cache is marked as containing an exclusively held, unmodified copy of the value and, when a requesting processing unit issues a message indicating that it desires to read the value, and the cache transmits a response indicating that the cache can source the value. The response is transmitted...

The data processor executes an instruction having a direction for write to a reference register of other instruction flow and an instruction having a direction for reference register invalidation. The data processor is arranged as a data processor having typical functions as an integrated whole of processors (CPU1 and CPU2) which execute simple instruction flows. When executing the instruction having a direction for write to a reference register of other instruction flow, the processor confirms ...

A computer-implemented method for enforcing cache coherence includes multicasting a cache request for a memory address from a requesting node without an ordering restriction over a network, collecting, by the requesting node, a combined snoop response of the cache request over a unidirectional ring embedded in the network, and enforcing cache coherence for the memory address at the requesting node, according to the combined snoop response.

A directory system directs cache line access requests from processors in a multi-processor system with a shared memory system through a cache line states directory. The cache line states directory stores a state value that identifies a cache line shared states word. The cache line shared states word identifies the processor that owns the cache line and the state of access of each processor that shares access to the cache line. A state value encoder encodes a cache line shared state word into a s...

A method and apparatus for tracking the fill status of subcache line locations during a cache line fill operation is provided. The tracking system monitors the data cycles of a burst read during a cache line fill, and sets indicators pertaining to which of the sub cache lines within the cache line have been filled. Cache control utilizes the indicators to make those sub cache lines that have been filled available to a processing system as they are filled, rather than waiting for the entire cache...

An apparatus comprises a first plurality of buffers configured to store operations belonging to a first virtual channel and a control circuit coupled to the first plurality of buffers. The first virtual channel includes first operations and second operations, wherein each of the first operations depend on at least one of the second operations during use. A first number of the first operations is less than or equal to a maximum. It is ambiguous, for a first received operation in the first virtual...

Methods and apparatus for maintaining cache coherency and reducing write-back traffic by using an enhanced MESI cache coherency protocol are disclosed. The enhanced MESI protocol includes the traditional MESI cache states (i.e., modified, exclusive, shared, invalid, and pending) as well as two additional cache states (i.e., enhanced modified and enhanced exclusive). An enhanced modified cache line is a cache line that is different than main memory and a copy of the cache line may be in another c...