4. Cache Organization and Coherency

4.7 Cache Block Ownership

The processor uses the following ownership rules:

• The processor assumes ownership of a cache block if the state of the cache block becomes DirtyExclusive. For a processor block read request, the processor assumes ownership of the block after receiving the last doubleword of a DirtyExclusive external block data response and an external ACK completion response. For a processor upgrade request, the processor assumes ownership of the block after receiving an external ACK completion response.
• The processor gives up ownership of a cache block if the state of the cache block changes to Invalid, CleanExclusive, or Shared.
• CleanExclusive and Shared cache blocks are always considered to be owned by memory.