Ex Parte Elwood

Board of Patent Appeals and Interferences

Mar 16, 2011

10994179 (B.P.A.I. Mar. 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.
10/994,179 11/22/2004 Matthew Paul Elwood 550-607 1191
23117 7590 03/17/2011
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON, VA 22203
EXAMINER
VICARY, KEITH E
ART UNIT PAPER NUMBER
2183
MAIL DATE DELIVERY MODE
03/17/2011 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 MATTHEW PAUL ELWOOD
____________

Appeal 2009-008550
Application 10/994,179
Technology Center 2100
____________

Before HOWARD B. BLANKENSHIP, JAY P. LUCAS, and
THU A. DANG, Administrative Patent Judges.

BLANKENSHIP, Administrative Patent Judge.

DECISION ON APPEAL1

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, or for filing a request for rehearing,
as recited in 37 C.F.R. § 41.52, begins to run from the “MAIL DATE”
(paper delivery mode) or the “NOTIFICATION DATE” (electronic delivery
mode) shown on the PTOL-90A cover letter attached to this decision.
Appeal 2009-008550
Application 10/994,179

2
STATEMENT OF THE CASE
This is an appeal under 35 U.S.C. § 134(a) from the Examiner’s final
rejection of claims 1-6 and 8-13, which are all the remaining claims. We
have jurisdiction under 35 U.S.C. § 6(b).
We affirm.

Invention
Appellant’s invention relates to a data processing system that includes
an instruction pipeline with a branch prediction mechanism. The branch
prediction mechanism includes a branch history register operating to store a
value which can be used to identify whether a newly encountered branch
instruction is one which has been previously encountered. If the branch is
not one which has previously been encountered, then a not taken prediction
is made. This not taken prediction is applied to both conditional and
unconditional branch instructions. The instruction set of the processor core
supports predication instructions which render unconditional branch
instructions conditional. Abstract.

Representative Claim
1. Apparatus for processing data, said apparatus having:

an instruction fetch unit operable to fetch one or more
program instructions starting from an instruction fetch address
into an instruction pipeline; and

a branch predictor operable to generate a prediction
indicative of whether or not a branch instruction fetched into
said instruction pipeline will be taken and so result in a non-
sequential change in said instruction fetch address, said
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Application 10/994,179

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instruction fetch unit being responsive to said prediction to
generate a next instruction fetch address; wherein

said branch predictor comprises:

at least one branch history register operative to store a
branch history value indicative of whether or not a
predetermined number of previously fetched branch instructions
were predicted taken or predicted not taken;

a branch instruction identifying circuit operable to
identify both conditionally executed branch instructions and
unconditionally executed branch instructions within said
instruction pipeline and to generate a branch history value
element for updating said branch history value only in respect
of a branch instruction for which no prediction based upon a
previous fetch of said branch instruction is available, wherein
for both conditionally executed branch instructions and
unconditionally executed branch instructions said branch
history value element is a prediction not taken prediction value;
and

said program instructions fetched to said instruction
pipeline include one or more predication instructions operable
to predicate a predetermined number of following program
instructions.

Prior Art
Beth Simon et al., Incorporating Predicate Information Into Branch
Predictors, Proc. Ninth Int’l Symposium on High-Performance Computer
Architecture (HPCA), 53-64 (2003) (‘Simon”).

Dionisios N. Pnevmatikatos and Gurindar S. Sohi, Guarded Execution
and Branch Prediction in Dynamic ILP Processors, Proc. 21st Annual Int’l
Symposium on Computer Architecture (ISCA), 120-129 (1994)
(“Pnevmatikatos”).

Appeal 2009-008550
Application 10/994,179

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Tse-Yu Yeh and Yale N. Patt, A Comprehensive Instruction Fetch
Mechanism for a Processor Supporting Speculative Execution, Proc. 25th
Annual Int’l Symposium on Microarchitecture (MICRO), 129-139 (1992)
(“Yeh”).

Examiner’s Rejections
Claims 1-6 and 8-13 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over Yeh, Simon, and Pnevmatikatos.

Claim Groupings
In view of Appellant’s arguments in the Appeal Brief, we will decide
the appeal on the basis of claim 1. See 37 C.F.R. § 41.37(c)(1)(vii).

ISSUE
Has Appellant shown that the Examiner erred in finding that the
combination of Yeh and Simon teaches “updating said branch history value
only in respect of a branch instruction for which no prediction based upon a
previous fetch of said branch instruction is available, wherein for both
conditionally executed branch instructions and unconditionally executed
branch instructions said branch history value element is a prediction not
taken prediction value” as recited in claim 1?

FINDINGS OF FACT
We rely on the findings of fact made by the Examiner in the Final
Rejection and Examiner’s Answer.

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Application 10/994,179

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PRINCIPLES OF LAW
Obviousness
“The 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, 416 (2007).
“Nonobviousness cannot be established by attacking references
individually where the rejection is based upon the teachings of a
combination of references.” In re Merck & Co., 800 F.2d 1091, 1097 (Fed.
Cir. 1986) (citing In re Keller, 642 F.2d 413, 425 (CCPA 1981)).

ANALYSIS
Appellant contends that Simon does not teach a default not-taken
prediction value for an unconditional branch. Br. 9.2 Appellant also
contends that Yeh always predicts that the unconditional branch is taken,
which leads a skilled person away from making a default not-taken
prediction value for the unconditional branch. Br. 11.
However, the Examiner relies on Yeh to teach a default not-taken
prediction value for a branch when no branch prediction based upon a
previous fetch is available (Ans. 5, 11-12). The Examiner relies on Simon to
teach a not-taken prediction value for an unconditional branch (Ans. 6, 12-
14). Appellant has not provided evidence or persuasive argument to rebut
the Examiner’s findings, nor demonstrated that the teachings of Yeh and

2 Appellant also refers to some unidentified “non-final office action” in the
Appeal Brief at page 9. However, the rejection on appeal is the rejection set
forth in the Final Rejection (mailed Feb. 19, 2008).
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Application 10/994,179

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Simon as combined in the rejection would fail to result in the feature upon
which Appellant relies.
Using the default not-taken prediction value for a branch as taught by
Yeh as a default for the unconditional branch as taught by Simon appears to
represent the combination of familiar elements according to known methods
that does no more than yield predictable results. Appellant has not provided
evidence or persuasive argument to the contrary.
With respect to Appellant’s allegation that Yeh would “lead away”
from the instant invention, we are not persuaded of error in the Examiner’s
analysis at page 16 of the Answer. What the prior art teaches and whether it
teaches toward or away from the claimed invention are determinations of
fact. Para-Ordnance Mfg. v. SGS Importers Int’l, Inc., 73 F.3d 1085, 1088
(Fed. Cir. 1995). The prior art’s mere disclosure of more than one
alternative does not constitute a teaching away from any of the alternatives
when the disclosure does not criticize, discredit, or otherwise discourage the
solution claimed. In re Fulton, 391 F.3d 1195, 1201 (Fed. Cir. 2004).
We sustain the § 103(a) rejection of claim 1. Appellant has not
provided arguments for separate patentability of claims 2-6 and 8-13, which
thus fall with claim 1.

CONCLUSION OF LAW
Appellant has not shown that the Examiner erred in finding that the
combination of Yeh and Simon teaches “updating said branch history value
only in respect of a branch instruction for which no prediction based upon a
previous fetch of said branch instruction is available, wherein for both
conditionally executed branch instructions and unconditionally executed
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branch instructions said branch history value element is a prediction not
taken prediction value” as recited in claim 1.

DECISION
The rejection of claims 1-6 and 8-13 under 35 U.S.C. § 103(a) as
being unpatentable over Yeh, Simon, and Pnevmatikatos 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). See 37 C.F.R.
§ 41.50(f).

AFFIRMED

msc

NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON VA 22203