Ex Parte Hewitt

Board of Patent Appeals and Interferences

Apr 21, 2008

10266152 (B.P.A.I. Apr. 21, 2008)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte LARRY D. HEWITT
____________

Appeal 2007-4085
Application 10/266,152
Technology Center 2100
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Decided: April 21, 2008
____________

Before JAMES D. THOMAS, JOSEPH L. DIXON
and ST. JOHN COURTENAY II, Administrative Patent Judges.

THOMAS, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134(a) from the Examiner’s final
rejection of claims 1 through 48. Since pages 2 and 12 of the Answer make
clear that the Examiner has withdrawn the rejection as to claims 31 through
48, claims 1 through 30 remain on appeal. We have jurisdiction under
35 U.S.C. § 6(b).
Appeal 2007-4085
Application 10/266,152

As best representative of the disclosed and claimed invention,
independent claim 1 is reproduced below:
1. A system for synchronizing clock signals, the system comprising:

a clock unit, wherein the clock unit is configured to receive a
reference clock signal and to output a plurality of domain clock signals,
wherein each of the domain clock signals has a different frequency with
respect to the other domain clock signals;

a synchronization unit, wherein the synchronization unit is configured
to receive the reference clock signal, wherein the synchronization unit is
configured to assert a synchronization pulse at a rate equivalent to a beat
frequency of the plurality of domain clock signals, and wherein clock signal
edges of each of the domain clock signals are aligned responsive to asserting
the synchronization pulse.

The following references are relied upon by the Examiner:
Self1 U.S. 6,047,383 Jan. 4, 2000
McClintock U.S. 5,606,276 Feb. 25, 1997
Price U.S. 5,450,458 Sep. 12, 1995
Jefferson U.S. 5,744,991 Apr. 28, 1998
Claims 1 through 30 stand rejected under 35 U.S.C. § 103. As
evidence of obviousness, the Examiner relies upon Self in view of
McClintock as to claims 1 through 4, 6 through 8, 14 through 19, 21 through
23, 29, and 30. To this combination of references the Examiner adds Price
as to claims 5 and 20, and the Examiner separately adds Jefferson as to
claims 9 through 11, 13, 24 through 26, and 28. Lastly, in the fourth stated

1 Page 3 of the Answer incorrectly lists the patent number of this reference as
6,074,383 instead of 6,047,383.
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rejection, the Examiner relies upon Self in view of McClintock, further in
view of Jefferson and Price as to claims 12 and 27.
Rather than repeat verbatim the positions of the Appellant and the
Examiner, reference is made to the Brief and Reply Brief for Appellant’s
positions and to the Answer for the Examiner’s positions.

OPINION
We affirm.
At the outset, we note that Appellant separately argues independent
claims 1 and 16 in a corresponding manner according to the positions set
forth at pages 6 through 23 of the principal Brief and the bulk of the Reply
Brief as well. No arguments are presented as to any dependent claim within
the first stated rejection relying upon Self in view of McClintock. Pages 31
through 34 of the principal Brief do not present separate arguments as to the
second through fourth stated rejections but instead collectively rely upon the
positions set forth with respect to the first stated rejection as to claim 1 and,
respectively, claim 16. A corresponding approach is taken in the Reply
Brief. Because independent claim 1 has corresponding teachings to those of
claim 16, we will treat the features of independent claim 1.
Appellant’s repeated urging in the Brief and Reply Brief that the
references respectively teach away from a feature of the claimed invention is
noted. As to the specific question of "teaching away," our reviewing court
in In re Gurley, 27 F.3d 551, 553 (Fed. Cir. 1994) stated "[a] reference may
be said to teach away when a person of ordinary skill, upon [examining] the
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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."
Beginning at page 6 of the Brief, Appellant variously argues that
McClintock teaches away from the subject matter of independent claim 1,
that the combination of Self and McClintock both teach away from the
proposed combination, that the proposed motivation would change the
principle of operation of Self, and that the proposed motivation would render
Self unsatisfactory for its intended purpose. Without repeating verbatim the
various positions set forth in the Brief, which are essentially repeated in the
Reply Brief, Appellant’s view is that McClintock teaches away from the use
of a system or reference clock, whereas Self teaches a reference clock signal
as an essential element. From our study of both references in light of these
urgings, we agree with Appellant’s views that, according to the above-noted
case law, we consider that the artisan would have been discouraged from
following the path set out in McClintock. Essentially, we agree with the
broader perspective that it would not have been obvious for an artisan to
have utilized the teachings within McClintock to have modified Self in
accordance with the reasoning set forth by the Examiner. In our view, it
would have been speculative to have concluded that the artisan would have
looked to or otherwise relied upon any teachings of the clocking circuits of
McClintock, which does not rely upon a reference clock signal, as a basis to
modify the teachings of Self, which does require the use of a reference
clock.
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On the other hand, notwithstanding these considerations, we sustain
the rejection of representative independent claim 1 because it appears that
the artisan would have found the subject matter of this claim obvious within
the teachings of Self alone within 35 U.S.C. § 103. It appears to us that both
the Examiner and the Appellant have given an incomplete consideration of
the teachings of Self.
Column 1 of Self begins a discussion of skewing a propagated clock
signal with respect to a master clock signal or any other propagated clock
signal. This is shown in figure 2 with respect to the various delays shown
there. The contribution of Self shown in figure 3 attempts to synchronize
the propagated clock signals with respect to the reference clock signal by
essentially modifying the electrical length of the feedback path in an effort
to ensure that the propagation traces themselves have the same length within
integrated circuit shown there.
What are most applicable to the subject matter of the present claims
on appeal are the showings in figures 4 and 5, as discussed at columns 7 and
8 of this reference. The various phase locked loops 410, 420, 430 in figure 4
comprise the claimed clock unit within the integrated circuit 400 such as to
produce a plurality of clock signals feeding respective component devices
shown to the right of this figure in such a manner that different frequencies
may be attributed to each of these clock signals. In correspondence with the
claimed synchronization unit, figure 4 provides programmable
dividers/counters 450, 460 which provide the functionality associated with
the two wherein clauses in this portion of representative claim 1 on appeal.
Again, it should be emphasized that the discussion at columns 7 and 8
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associated with figures 4 and 5 emphasize the synchronization of the
respective rising edges, as an example of the propagated clock signals, with
respect to the same reference clock signal which feeds both the
synchronization unit and the respective phase locked loop or clocking units
themselves which are said to provide different clocking frequencies. Figure
5 shows the alignment according to the requirement of the edges being
aligned at the end of claim 1 on appeal.
What is also significant according to these teachings is that the
claimed equivalent beat frequency among the plurality of the main clock
signals is met by the teachings of the programmable dividers/counters which
provide the claimed synchronization pulse or pulses. As discussed in the
middle of page 15 of the Specification as filed, the beat frequency of the
clock patterns may be defined as the frequency of the reference clock itself
divided by a number N. This is essentially the same teaching provided at
columns 7 and 8 as well as the abstract of Self even though the term “beat
frequency” is not expressly set forth among those teachings. Self appears to
teach in words different than utilizing the beat frequency language per se to
achieve the synchronization unit functionality of synchronizing at an
equivalent rate to the claimed beat frequency since both clock frequencies
shown in figure 5, for example, commonly or equivalently rely upon the
same reference signal among the circuits in figure 4. The discussion
beginning in the paragraph bridging columns 7 and 8 through the discussion
at the end of the patent essentially emphasize this.
In view of the foregoing, the decision of the Examiner rejecting
claims 1 through 30 under 35 U.S.C. § 103 is affirmed.
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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.
§ 1.136(a)(1)(iv).
AFFIRMED

pgc

B. Noel Kivlin
Conley, Rose, & Tayon, P.C.
P.O. Box 398
Austin TX 78767
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