摘要:
In a time-shared bus computer system with processors having cache memories, an adjustable invalidation queue for use in the cache memories. The invalidation queue has adjustable upper and lower limit positions that define when the queue is logically full and logically empty, respectively. The queue is flushed down to the lower limit when the contents of the queue attain the upper limit. During the queue flushing operation, WRITE requests on the bus are RETRYed. The computer maintenance system sets the upper and lower limits at system initialization time to optimize system performance under maximum bus traffic conditions.
摘要:
An Invalidation Queue (IQ) arrangement in a computer system having Main Memory and, Cache-Memory, with a pair of intermediate main-buses this IQ arrangement comprising: a pair of split IQ ASIC Arrays disposed between each Cache-Memory and the main-buses and being adapted to assure identical data in all identical memory addresses in different caches, and to "remember" write-operations along the buses and to execute invalidation sequences for any Cache-Memory unit as dictated by that Cache-Memory unit.
摘要:
By expanding the cache address invalidation queue into bit slices for holding odd invalidation addresses and even invalidation addresses and also by providing a more efficient series of transition cycles to accomplish cache address invalidations both during a cache hit or a cache miss cycle, the present architecture and methodology permits a faster cycle of cache address invalidations when required and also permits a higher frequency of processor access to cache without the processor being completely locked out from cache memory access during heavy traffic and high level of cache invalidation conditions.
摘要:
A system and circuitry is provided by which certain selected embedded pins of an integrated circuit gate array may be provided with dual functions, that is to say, they may act either as receivers of an externally sourced input signal or as transmitters of an internally generated output signal. Each selected input/output pin is controlled by an associated flip-flop residing in a chain of flip-flops so that an associated flip-flop will determine the condition of two buffer-drivers attached to each input/output pin. While the first buffer-driver is tri-stated (disabled), then the embedded pin operates as an input receiving function. When the first buffer-driver is enabled, the embedded I/O pin operates as the conveyer of an output signal from the internal output logic.
摘要:
A "bit-sliced" construction cache module dictates dual TAG RAM Structures and dual invalidation queues, yielding enhanced performance: putting half the TAG array in each of two cache arrays, and allowing each to handle only one-half of the possible address values. Preferably, one half-module handles ZERO least-significant bits and the other handles ONE least-significant bits. Processor operations and invalidation operations can be "overlapped", and even operate simultaneously.
摘要:
A method and technique for inserting additive logic and flip-flops into the architecture of a gate array chip package whereby spare input and output pins can later be used to alter the logic functions by either disabling or enabling certain logic units internal to the chip by external signal injection.
摘要:
A "bit-sliced" construction of our cache module dictates dual TAG RAM structures and dual invalidation queues, yielding enhanced performance. By putting half the TAG array in each of two cache arrays, and allowing each to handle only one-half of the possible address values, processor operations and invalidation operations can be "overlapped", and even operate simultaneously.
摘要:
A message transfer system between multiple processors in a network. Each processor includes an interprocessor communications (IPC) hardware unit having an unique address count. An address count generator in a designated IPC hardware unit generates a sequence of binary count numbers such that when the generated count number matches the address of the IPC hardware unit, then that particular hardware unit and its associated processor are granted a time period of bus access for sending messages on the IPC network bus to other processors. Messages on the IPC network bus can be received by an IPC hardware unit at any time irrespective of the generated count number. Any sending processor that has bus access can concurrently provide multiple messages where each of the multiple messages is directed to each particular processor for reception. Thus one sender, with bus access, can communicate with multiple receivers during its transmission onto the IPC network bus connecting the processors.
摘要:
Arbitration and control circuitry for monitoring the two processors sharing a system bus to insure fair access to system resources and to sense error conditions which occur in order to hold access for the processor involved until the error condition is cleared. The arbitration circuitry provides for two levels of bus access requests where one level involves normal requests and a second level involves priority request which take precedence over normal requests.
摘要:
A method and technique for inserting additive logic into the architecture of a gate array chip package whereby spare input and output pins can later be used to alter the logic functions by either disabling or enabling certain logic units internal to the chip by external signal injection.