Patent ID: 6023747
Filing Date: 2000-02-08
Classification: G06F

Abstract:
A method of managing a cache including a plurality of entries, each of said plurality of entries having a respective coherency state associated therewith, said method comprising the steps of:in response to receipt at said cache of a first cache operation request specifying a particular entry among said plurality of entries, performing a single access of a coherency state associated with said particular entry;thereafter, in response to receipt at said cache of a second cache operation request, determining if servicing said second cache operation request requires replacement of one of said plurality of entries;in response to a determination that servicing of said second cache operation request requires replacement of one of said plurality of entries, identifying an entry among said plurality of entries for replacement; andif said identified entry is said particular entry, replacing said identified entry only after servicing said first operation request, said replacing step including the step of writing contents of said identified entry into a lower level memory in association with an updated coherency state derived from said coherency state obtained during said single access.