Cache memory system and method using dynamically allocated dirty mask space

摘要

A cache memory system includes a cache memory including a plurality of cache memory lines and a dirty buffer including a plurality of dirty masks. A cache controller is configured to allocate one of the dirty masks to each of the cache memory lines when a write to the respective cache memory line is not a full write to that cache memory line. Each of the dirty masks indicates dirty states of data units in one of the cache memory lines. The cache controller may include a dirty buffer index which stores an identification (ID) information that associates the dirty masks with the cache memory lines to which the dirty masks are allocated. A cache line may include a fully dirty flag indicating when each byte in that cache line is dirty, so that a dirty mask does not need to be allocated for that cache line.

主权项

1. A cache memory system comprising:
a cache memory including a plurality of cache memory lines; a dirty buffer including a plurality of dirty masks; and a cache controller configured to:
allocate one of the plurality of dirty masks to a respective cache memory line when a write to the respective cache memory line is not a full write, wherein the one of the plurality of dirty masks indicates dirty states of data units in the respective cache memory line,store identification (ID) information that associates the one of the plurality of dirty masks with the respective cache memory line to which the one of the plurality of dirty masks is allocated,de-allocate the one of the plurality of dirty masks from the respective cache memory line when each of the data units in the respective cache memory line is dirty, andde-allocate the one of the plurality of dirty masks from the respective cache memory line when each of the data units in the respective cache memory line is not dirty.