摘要 |
A memory cache apparatus compatible with a wide variety of bus transfer types including non-burst and burst transfers. In burst mode, a "demand word first" wrapped around quad fetch order is supported. The cache memory system decouples the main memory subsystem from the host data bus so as to accommodate parallel cache-hit and system memory transfer operations for increased system speed and to hide system memory write-back cycles from the microprocessor. Differences in the speed of the local and system buses are accommodated, and an easy migration path from non-burst mode microprocessor based systems to burst mode microprocessor based systems is provided. Various memory organizations are accommodated including direct-mapped or one-way set associative, two-way set associative, and four-way set associative.
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