| 摘要 |
Disclosed is a snoop filter that stores only entries that have an exclusive state, ie that are exclusively owned by a processor, and updates an entry if a request changes the ownership of a line associated with the entry. The coherency engine operating the snoop filter may have a sequencing rule that decouples a read request from a write request. The entry may be removed when a read request is received and changing the ownership of a line if a processor write results in a hit. The coherency engine may allocate a new entry in the filter to a processor and send a invalidating message to all processors with tracked lines, if the processor issues a write request that result in a miss. The coherency engine may send an invalidating message to a current owner of a line if a request is a hit. The coherency engine may have a Goto_S unit to change an exclusive stage of a line. |
