Directory
CoupledL2 adopts a directory-based coherence implementation, utilizing the directory to record metadata information of data blocks within the L2 Cache. As shown in 此图, the Directory checks whether the L2 Cache stores the requested data block (hit or miss) based on the tag and set of the read request. If it hits, the metadata information of that data block is returned. If it misses, an invalid way or a way to be replaced is selected, and the metadata information of that way's data is returned. After processing the request, the new directory information is written back to the Directory for updates.
