Patent ID: 7844777

Claim:
An apparatus comprising: a host controller to be coupled to a port multiplier, wherein the port multiplier is to have a plurality of devices coupled thereto, the host controller including: a cache memory storing a plurality of entries, each entry including an address field configured to store a command issued (CI) identifier and a port multiplier port (PMP) identifier, and a data field configured to store a command header (CH) portion having data associated with a command from the host controller to one of the plurality of devices and a physical region descriptor (PRD) portion configured to store address information associated with a next address for data transfer with regard to the command, wherein the cache memory includes logic configured to determine if the CH portion of an incoming entry is of a higher priority than at least one of the stored entries or if one of the stored entries is to be selected for certain eviction, based on a single device error (SDE) indication, and if so, evict the at least one of the stored entries and store the incoming entry.