A method for caching specified data in an n-way set associative memory with a copy-back update policy consists of the following steps. First, a row of the associative memory, organized as a plurality of rows and having n ways per row, is selected according to the main memory address of the specified data. The main memory provides primary storage for the data being cached. If one of the ways of the selected row holds invalid data, the specified data is cached in the way holding the invalid data a...

An integrated circuit memory device includes a quad-port cache memory device and a higher capacity supplemental memory device. These memory devices operate collectively as a high speed FIFO having fast fall through capability and extended data capacity. The FIFO does not require complex arbitration circuitry to oversee reading and writing operations. The supplemental memory device may be an embedded on-chip memory device or a separate off-chip memory device (e.g., DRAM, SRAM). The quad-port cach...

A high speed DRAM cache architecture. One disclosed embodiment includes a multiplexed bus interface to interface with a multiplexed bus. A cache control circuit drives a row address portion of an address on the multiplexed bus interface and a command to open a memory page containing data for a plurality of ways. The cache control circuit subsequently drives a column address including at least a way indicator to the multiplexed bus interface.

The vector unit 21 outputs a first flash address to the flash address array 24. The vector unit 31 outputs a second flash address to the flash address array 34. In the master unit 2, the flash address array 24 compares an address registered in a cache with the first flash address. In the slave unit 3, the flash address array 34 compares the address registered in the cache with the second flash address. When said first flash address coincides with said address registered in said cache, the flash ...

A liquid delivery apparatus includes a vessel having an inlet and an outlet, and a valve between the vessel and the outlet. The valve has an opening, a closure member for closing the opening, and a biasing means to hold the valve in a normally-closed position. A valve control mechanism controls operation of the valve in response to pressure of liquid and air in the vessel. A transmitting means transmits the pressure to the valve control mechanism. The valve control mechanism includes a moveable ...

In a computer system having a storage system in which storage units are hierarchically configured, a management method for accurately grasping the capacity available to the computer is disclosed.In a computer system in which a management computer manages the capacities of storage units for storing data used by the computer, the management method is typically realized by a storage management system comprising a group of first-level storage units each containing volumes for storing data used by th...

In one embodiment, a wordline decoder provides access to cache memory locations when addresses are bypassed directly from arithmetic circuitry in redundant form. The wordline decoder is also designed to provide access to cache memory locations when addresses are received from registers in an unsigned binary form. The combined functionality is provided in a pre-decode circuit by selectively replacing one of a plurality of redundant bit vectors with a constant bit vector when redundant addressing ...

A method and system for improving the performance of a cache. The cache may include a tag entry that identifies the previously requested address by the processor whose data was not located in the cache. If the processor requests that address a second time, then there is a significant probability that the address will be accessed again. When the processor requests the address identified by the tag entry a second time, the cache is updated by inserting the data located at that address and evicting...

Method and apparatus for increasing the number of real memory addresses accessible through a translational look-aside buffer (TLB) by a multi thread CPU. The buffer entries include a virtual address, a real address and a special mode bit indicating whether the address represents one of a plurality of threads being processed by the CPU. If the special mode bit is set, the real address associated with the virtual address higher order bits are concatenated with the thread identification number bein...

A multiprocessor system includes a plurality of data processing nodes. Each node has a processor coupled to a system memory, a cache memory, and a cache directory. The cache directory contains cache coherency information for a predetermined range of system memory addresses. An interconnection enables the nodes to exchange messages. A node initiating a function shipping request identifies an intermediate destination directory based on a list of the function's operands and sends a message indicati...