Appeal No. 2004-0538
Application No. 09/976,495
a clear disavowal of claim scope.” Id.
Claim 1 contains the limitations of “a cache flushing engine” and “said first system
control unit responsive to an update of said one of said plurality of caches operatively
connected therewith to flush said update to said second system control unit and assure
said update is entered into said memory.” The flush command is discussed on page 5 of
the appellants’ specification as a command that will “force, or ‘flush’, the local cache 205
to write back the new values for locations… to the temporary buffer 315 in the home
node.” This explanation is constant with the dictionary definition of flush “to clear the
contents of a buffer, saving changed data in disk.”2 The definition also seems to be
consistent with the meaning used in the prior art, for example column 22, lines 23 to 26 of
Hagersten, states “Flush requests cause copies of the coherency unit to be invalidated.
Modified copies are returned to the home node.” Thus, we consider the scope of claim 1
to include a flush engine which forces a write of data from the cache associated with a
first control unit to memory associated with a second control unit.
We find that the AAPA teaches a multiprocessor system where data is kept by a
home node in a home memory and the other nodes may contain copies of the data. The
home node maintains a directory of nodes that have copies. If a node does not have a
copy it requests it from the home node. See page 1 of appellants’ specification. If the
home node does not have the most up to date copy (stale copy) the home node directs
the requesting node to the node that does have an up to date copy. See appellants’
specification page 2. The AAPA states, “the home node employs a coherence protocol to
2 Definition from Microsoft Press, Computer Dictionary, 1994.
-6-
Page: Previous 1 2 3 4 5 6 7 8 9 Next
Last modified: November 3, 2007