Emulex Design & Manufacturing Corporation

Emulex Corporation

Eric David Peel

Qing Xue

Bradley Eugene Roach

Sam S Su

David James Duckman

Steven Gerard LeMire

Eddie Miller

Stephen Eugene Holness

Embodiments of the present invention are directed to a scheme in which information as to the future behavior of particular software is used in order to optimize cache management and reduce cache pollution. Accordingly, a certain type of data can be defined as 'short life data' by using knowledge of the expected behavior of particular software. Short life data can be a type of data which, according to the ordinary expected operation of the software, is not expected to be used by the software often in the future. Data blocks which are to be stored in the cache can be examined to determine if they are short life data blocks. If the data blocks are in fact short life data blocks they can be stored only in a particular short life area of the cache.

Cache pollution avoidance

A DMA (Direct Memory Access) Exchange Block (DXB) processor may include a receive processor for writing data from a local memory to a host memory over a bus, e.g., a Peripheral Component Interconnect Extended (PCI/X) bus, and a transmit processor for writing data retrieved from the host memory over the bus to the local memory. Each processor may include a high priority queue and a normal priority queue. A controlling program generates DXBs, each of which include a tag assigned by the controlling program and memory descriptors corresponding to a direct memory access operation. The memory descriptor may include a host memory descriptor (address/length) and one or more local memory descriptors. The controlling program writes a DXB to one of the queues in a cache line spill operation. The transfer processor may include two channel registers, enabling the processor to perform two PCI/X data transfers simultaneously.

Direct memory access (DMA) transfer buffer processor

A memory controller for a multi-byte burst memory device may control access to memory based on parameters set up by a client. These parameters may include a byte address and a byte count that indicates the number of bytes the client is requesting from memory. These values, and an integer representing the number of bytes in a burst-accessed word, may be operated on to produce a word that may be used to identify valid bytes in the burst-accessed word.

Method for determining valid bytes for multiple-byte burst memories

The present invention is directed to a memory data interface for transferring data between a memory device and an integrated circuit, whereby, in accordance with one aspect of the present invention, the memory data interface includes a data selector for selecting and normalizing data from memory devices operating at different data transfer timing, and, in accordance with another aspect of the present invention, the memory data interface is capable of transferring data between a memory device and an integrated circuit having a different bus width than the memory device. In accordance with yet another aspect of the present invention, the memory data interface is capable of transferring data between an integrated circuit and a variety of different memory device having different data bus widths. Finally, in accordance with yet another aspect of the present invention, the memory data interface is capable of transferring data between an integrated circuit and a variety of memory devices having different bus widths and different data transfer timing.

Memory data interface

A data formatter includes a shift register and a pointer manager. The shift register receives data from a providing RAM and shifts that data in response to reading data from the providing RAM and writing data to a receiving FIFO. A pointer manager maintains a pointer that points to a first valid byte in a sub-block of data into the correct bytes lanes of the FIFO by moving the pointer as data is shifted into and out of the shift register.

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Costa Mesa, CA, United States of America

Eric David Peel