Directory
CoupledL2 adopts a directory-based coherence implementation, utilizing a directory to record metadata information of data blocks within the L2 Cache. As shown in 此图, the Directory will look up whether the L2 Cache stores the data block (whether it is a hit) based on the tag and set of the read request. If it is a hit, it returns the metadata information of the data block. If it is a miss, it selects an invalid way/a way to be replaced and returns the metadata information of the data in that way. After the request processing is complete, the new directory information will be written to the Directory for updating.
