A SCI controller manages responses and requests between SCI
interconnection rings and memory access controllers. The SCI controller
includes a request activation queue that stores information about the
requests until the SCI rings have the resources to handle the requests.
The controller also has a response activation queue that stores
information about the responses until the memory access controller is
accessible. The queues do not store the request and response packets, but
rather store information that is used to construct the request and
response packets. The SCI controller also has a contents addressable
memory or CAM that checks for an address match between the current
requests and responses and previous requests and responses. A table
stores more specific information about the previous requests.