Ex Parte Rau

Board of Patent Appeals and Interferences

Jun 16, 2011

11021707 (B.P.A.I. Jun. 16, 2011)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/021,707 12/23/2004 Stefan Rau 6570P187 5736
45062 7590 06/16/2011
SAP/BSTZ
BLAKELY SOKOLOFF TAYLOR & ZAFMAN LLP
1279 OAKMEAD PARKWAY
SUNNYVALE, CA 94085-4040
EXAMINER
BIRKHIMER, CHRISTOPHER D
ART UNIT PAPER NUMBER
2186
MAIL DATE DELIVERY MODE
06/16/2011 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
________________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
________________

Ex parte STEFAN RAU
________________

Appeal 2009-008251
Application 11/021,707
Technology Center 2100
________________

Before JEAN R. HOMERE, JAY P. LUCAS, and THU A. DANG,
Administrative Patent Judges.

DANG, Administrative Patent Judge.

DECISION ON APPEAL

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Application 11/021,707

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STATEMENT OF THE CASE
Appellant appeals under 35 U.S.C. § 134(a) from the Examiner’s
Final Rejection of claims 1-5 and 7-20. Claim 6 has been canceled. We
have jurisdiction under 35 U.S.C. § 6(b).
We affirm.

A. INVENTION
According to Appellant, the present invention relates generally to
caching and, in particular, to a least recently used (LRU) software cache
(Spec. 2, ¶ [0001]).

B. ILLUSTRATIVE CLAIM
Claim 1 is exemplary and reproduced below:
1. A method of updating a data cache having a
plurality of rows, the method comprising:

maintaining a list of the rows, the list
including a plurality of entries, each entry
corresponding to a row and having a key uniquely
identifying the row, and further having a count
indicating an age of the row;

sorting the entries by their key;

searching the list for an entry having a key
to a row to be updated if found or added if not
found;
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if the entry having the key to the row to be
updated is found:

removing the entry from the list;

sorting the remaining entries by their
count, so that the entry at the beginning of
the list is for the oldest row, and the entry at
the end of the list is for the newest row;

appending a new entry at the end of
the list that replaces the removed entry, the
new entry having the same key as the
removed entry, and a count indicating the
corresponding row is the newest; and

updating the corresponding row in the
data cache.

C. REJECTION
The prior art relied upon by the Examiner in rejecting the claims on
appeal is:

Moenne-Loccoz US 5,933,848 Aug. 13, 1999
Ish US 5,778,430 Jul. 07, 1998

Claims 1-5, 7-13, and 15-20 stand rejected under 35 U.S.C. § 103(a)
as being unpatentable over the combined teachings of Moenne-Loccoz and
Ish.
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Claim 14 stands rejected under 35 U.S .C. § 103(a) as being
unpatentable over the combined teachings Moenne-Loccoz and Ish, and
further in view of Admitted Prior Art (APA).

II. ISSUE
Has the Examiner erred in concluding that the combined teachings of
Moenne-Loccoz and Ish would have suggested a method of updating a data
cache which includes a step of “removing the entry from the list” (claim 1)?

III. FINDINGS OF FACT
Moenne-Loccoz
1. Moenne-Loccoz discloses a cache system to facilitate processor
access to data, wherein a portion of system memory is organized as
cache memory and a cache manager is provided that exists separately
of the processor and the system memory (Abstract; Fig. 1).
2. At the heart of the cache manager is a cache table that contains an
entry for each addressable location of the cache memory as identified
by its address, wherein each entry contains the location address, the id
number of the data block last held in that address and status flags
indicating the current status of the block (col. 6, ll. 6-13; Fig. 5).
3. If a requested block is found to be in the cache memory and valid, the
operating system updates the block in cache, and the cache manager
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controller updates the cache table to show that the block has been
modified (col. 8, ll. 6-12).
Ish
4. Ish discloses a cache management method wherein a timestamp
member identifies a time at which the cache line was last accessed
(col. 6, ll. 13-15), wherein the oldest cache lines bubble to the top of
the heap more quickly since they are not being used frequently (col. 7,
ll. 53-55).

IV. ANALYSIS
Claims 1-5, 7-13, and 15-20
Appellant argues that “Moenne-Loccoz fails to teach or suggest any
updating of an entry of cache table 53 which includes a removing of an
entry from cache table 53” (App. Br. 4). According to Appellant, “the
number of entries in cache table 53 is fixed at the number of addressable
locations in the cache it represents,” and thus “Moenne-Loccoz precludes
the possibility that any entries of cache table 53 may be removed from cache
table 53” (id.).
However, the Examiner finds that as Appellant “acknowledges”,
“Moenne-Loccoz teaches changing or updating the status flags in the cache
table that correspond to an entry in the cache” (Ans. 15). According to the
Examiner, “[b]y updating the status of one of the entries in the list of rows of
the cache the previous entry in the list is effectively removed from the list”
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since “[t]he entry is removed because at the newly changed location is new
data that was not previously there” (id.). Thus, the Examiner finds that
“[t]he act of updating an entry in the list is the same as removing an entry
from the list since after the change an entry that used to be in the list is
replaced by a new entry” (id.).
To determine whether the references would have suggested a method
of updating a data cache which includes a step of “removing the entry from
the list” (claim 1), we give the claims their broadest reasonable
interpretation consistent with the Specification. See In re Bigio, 381 F.3d
1320, 1324 (Fed. Cir. 2004). However, we will not read limitations from the
Specification into the claims. In re Van Geuns, 988 F.2d 1181, 1184 (Fed.
Cir. 1993).
Claim 1 does not define what “removing” is to mean, represent or
include, other than the entry is removed from the list in updating. In fact,
claim 1 does not even define “entry” except that the list includes “a plurality
of entries, each entry corresponding to a row.”
Though Appellant argues that “the number of entries in cache table 53
is fixed at the number of addressable locations in the cache it represents”
(App. Br. 4), claim 1 does not preclude a cache table having a fixed number
of entries. In particular, having a fixed number of entries does not mean that
the entries (and the data therein) must be fixed/unchanged. In fact, claim 1
does not require that an “entry” being removed from the list be one of the
fixed location “entries” in cache table 53 as labeled by Moenne-Loccoz.
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That is, though Moenne-Loccoz seems to define the “entries” with the fixed
number as the particular fixed locations in the rows where data can be
entered, we accord the claimed “entry” its broadest reasonable interpretation
consistent with the Specification and specifically defined by the claims as
any data entered in the list corresponding to a row on the list, wherein the
entered data is removed or deleted upon updating. Thus, contrary to
Appellant’s contention that the “entries” of Moenne-Loccoz are fixed in
number, in view of our broad but reasonable interpretation, we will not limit
an “entry” to those with the fixed number corresponding to the addressable
locations as labeled by Moenne-Loccoz but rather interpret “entry” as any
entered data in the cache table that corresponds to a row.
Moenne-Loccoz discloses a cache table comprising a plurality of rows
and data entered corresponding to the rows (FF 1-2), wherein the cache table
is updated to show that data has been changed (FF 3). We find Moenne-
Loccoz teaches maintaining a table comprised of rows, the table including
data entered for the rows, wherein the entered data in the table is updated.
We also find such updating to inherently comprise replacing the old entered
data in the cache table with newly entered data, wherein the old data is
removed. In view of our claim interpretation above, we find Moenne-
Loccoz would have at the least suggested removing an entry (old entered
data to be replaced) from the cache table (list) when updating. Accordingly,
we find no error in the Examiner’s conclusion that the combined teachings
of Moenne-Loccoz and Ish would have suggested a method of updating a
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data cache which includes a step of “removing the entry from the list,” as
required by claim 1.
Though Appellant also argues that the references cannot be combined
because the combination “has no reasonable expectation of success” (App.
Br. 6-7) when “an entry with a fixed number of entries cannot have another
entry appended to it” (App. Br. 7-8), we agree with the Examiner that one
skilled in the art would predictably combine the teachings (Ans. 6 and 16-
18). As set forth by the Examiner, Appellant’s argument of “no reasonable
expectation of success” is without merit because “Moenne-Loccoz teaches
removing an entry from a list while still retaining the same number of
entries” wherein “appending the newly changed entry at the end of the list
would not result in a list with one to [sic] many entries” (Ans. 17). That is,
we agree that having a fixed number of entries does not mean having the
same exact entries, and thus, does not preclude having removed and
appended entries.
We also agree with the Examiner’s explicit motivation that combining
the references would be obvious since “there is a continuing need in the art
for new disk caching methods and structures, offering lower overhead and
higher performance” (Ans. 6). The Supreme Court has stated that “[t]he
combination of familiar elements according to known methods is likely to be
obvious when it does no more than yield predictable results.” KSR Int’l Co.
v. Teleflex Inc., 550 U.S. 398, 419 (2007).
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Though Appellant also contends that the combination “teaches away”
(App. Br. 6-7), “[a] reference may be said to teach away when a person of
ordinary skill, upon reading the reference, would be discouraged from
following the path set out in the reference, or would be led in a direction
divergent from the path that was taken by the applicant.” In re Gurley, 27
F.3d 551, 553 (Fed. Cir. 1994). Here, the Appellant appears to have viewed
the reference from a different perspective than the Examiner. The issue here
is not whether Ish would add more entries but whether a person of ordinary
skill, upon reading Moenne-Loccoz, would be discouraged from using
timestamps as taught by Ish.
That is, Ish discloses a providing a timestamp for a cache entry
wherein the entries are sorted thereby (FF 4). We find that Ish “is not so
credible or persuasive of a contrary teaching that it would have deterred the
skilled artisan from using [its] teachings,” In re Young, 927 F.2d 588, 592
(Fed. Cir. 1991), in combination with those of Moenne-Loccoz to reject
claim 1.
Thus, we conclude that the Examiner did not err in rejecting
independent claim 1, and claims 2-5, 7-13, and 15-20 falling therewith
under 35 U.S.C. § 103(a) over Moenne-Loccoz in view of Ish.
Claim 14
Appellant does not provide arguments for claim 14 separate from
those of claim 13 from which it depends (App. Br. 8). As Appellant has not
shown the Examiner erred in rejecting claim 13, we affirm the rejection of
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claim 14 over the combined teachings of Moenne-Loccoz and Ish and
further in view of AAPA under 35 U.S .C. § 103(a).

V. CONCLUSION AND DECISION
Appellant has not shown that the Examiner erred in concluding that
claims 1-5 and 7-20 are unpatentable under 35 U.S.C. § 103(a). The
Examiner’s decision rejecting claims 1-5 and 7-20 under 35 U.S.C. § 103(a)
is affirmed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED

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