Ex Parte Sriram

Board of Patent Appeals and Interferences

Oct 30, 2008

10610855 (B.P.A.I. Oct. 30, 2008)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte MYSORE SRIRAM
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Appeal 2008-3834
Application 10/610,8551
Technology Center 2800
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Decided: October 30, 2008
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Before KENNETH W. HAIRSTON, SCOTT R. BOALICK,
and JOHN A. JEFFERY, Administrative Patent Judges.

HAIRSTON, Administrative Patent Judge.

DECISION ON APPEAL

Appellant appeals under 35 U.S.C. § 134 from a final rejection of
claims 1 to 29. We have jurisdiction under 35 U.S.C. § 6(b).
We will sustain the rejection.

1 Application filed June 30, 2003. The real party in interest is Intel
Corporation.

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THE INVENTION
Appellant’s claimed invention is directed to a system and method of
designing integrated circuits with an electronic design automation (“EDA”)
tool (Spec. 2). The system and method re-route circuit design signal paths to
allow for product changes and circuit upgrades using two different
approaches (Spec. 2). In the first approach, alternative signal path routing is
performed using a “topologically equivalent path” which is enumerated by
“sliding” path segments of the signal path by offset amounts in one or more
directions to produce a replacement path (see claim 1 on appeal; Fig. 2;
Spec. 7-9). In the second approach, alternative signal path routing is
performed by generating a “topologically morphed version of the signal
path” which is selected as the replacement path (see claim 9 on appeal; Fig.
3; Spec. 9-10).
Claims 1 and 9 are representative of the claims on appeal, and they
read as follows:
1. A signal routing method comprising:
enumerating for a signal path of a circuit design, one or more alternate
paths that are topological equivalent to the signal path, by sliding each of a
plurality path segments of the signal path by one or more offset amounts in
each of one or more directions; and
selecting a replacement path for the signal path from the one or more
enumerated topological equivalent alternate paths.
9. A signal routing method comprising:
generating a first topologically morphed version of a signal path of a
circuit design; and
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selecting a replacement path for the signal path using the first
topologically morphed version of the signal path.

THE REJECTION
The prior art relied upon by the Examiner in rejecting the claims on
appeal is:
Nitta et al. (“Nitta”) US 6,415,527 B2 July 2, 2002

The Examiner rejected claims 1 to 29 under 35 U.S.C. § 102(e) as
being anticipated based upon the teachings of Nitta.2

ISSUES
1. Appellant contends that the applied reference to Nitta does not
teach the first signal routing approach of “‘enumerating for a signal path of a
circuit design, one or more alternate paths that are topological equivalent to
the signal path, by sliding each of a plurality path segments of the signal
path by one or more offset amounts in each of one or more directions’” as
recited in independent claims 1, 16, and 23 (App. Br. 5-7; Reply Br. 2-9).
2. Appellant also contends that Nitta does not teach the second signal
routing approach of “generating a first topologically morphed version of a
signal path of a circuit design” as recited in independent claims 9, 19, and 26
(App. Br. 7; Reply Br. 9-10).

2 Although not made by the Examiner in the Final Rejection, we note that a
rejection would also have been appropriate under 35 U.S.C. § 102(a) based
on the July 2, 2002, publication date of Nitta, which is prior to Appellant’s
application filing date of June 30, 2003.

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Thus, the anticipation issues before us concern whether or not the
applied reference to Nitta describes the “enumeration” and the “morphing”
signal routing approaches as set forth in the claims on appeal. Rather than
repeat the arguments of Appellant or the Examiner, we refer to the Brief3
and the Answer4 for their respective details. In this decision, we have
considered only those arguments actually made by Appellant. Arguments
which Appellant could have made but did not make in the Briefs have not
been considered and are deemed to be waived. See 37 C.F.R.
§ 41.37(c)(1)(vii).
We note that Appellant has not separately argued the merits of claims
2 to 8 or 10 to 29, and instead Appellant relies on the arguments presented
with respect to the patentability of claims 1 and 9 (see App. Br. 7; Reply Br.
9-10). We select claim 1 as representative of the group consisting of claims
1 to 8, 16 to 18, and 23 to 25, and select claim 9 as representative of the
group consisting of claims 9 to 15, 19 to 22, and 26 to 29. Thus, claims 2 to
8, 16 to 18, and 23 to 25 stand or fall with representative claim 1, and claims
10 to 15, 19 to 22, and 26 to 29 stand or fall with representative claim 9. See
37 C.F.R. § 41.37(c)(1)(vii). Accordingly, we confine our discussion to
claims 1 and 9, with the other claims standing or falling with their respective
representative claim. See id.

3 We refer to the most recent Appeal Brief filed April 30, 2007, and the
Reply Brief filed May 22, 2007, throughout this opinion.

4 We refer to the Examiner’s Answer mailed May 10, 2007, throughout this
opinion.
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FINDINGS OF FACT
1. As indicated supra, Appellant describes and claims a system and
method of routing alternative signal paths applicable to integrated circuit
design, and in particular dealing with “function block changes … or routing
space shrinkages, e.g.[,] due to shrinkage of a design” between successive
generations of an integrated circuit design (Spec. 2, see also App. Br. 2-3).
2. Appellant describes the term “topological equivalent” at page 7,
line 24 to page 8, line 3 of the Specification:
[A] signal path is considered to be topologically equivalent to
another signal path, if the two signal paths have a 1:1
correspondence for path segments. That is, the two
topologically equivalent signal paths necessarily have the same
number of path segments, and the corresponding path segments
are necessarily parallel to one another (similarly oriented).

3. Appellant describes the concept of “topology morphing” at
page 9, line 24 to page 10, line 2 of the Specification (describing
Figure 3):
[T]he topology of signal path 210 may be morphed by breaking
path segment 216 into two portions 216a and 216c at
breakpoint 218, and sliding them away from each other in the
directions of 252 and 254. The two portions 216a and 216c are
connected through the addition/insertion of bridge portion
216b.

4. Nitta teaches a method and system for routing signal paths using
computer-aided automatic layout design for integrated circuits (Abstract;
col. 1, ll. 11-30).

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5. Nitta was cited by the Examiner as teaching a signal routing
method and apparatus which enumerates an alternate signal path which is a
topological equivalent to the original signal path, and which enumerates the
alternate signal path by sliding a plurality of path segments (Ans. 4-6). The
Examiner relied upon Figures 9, 10, and 12A through C and the
accompanying text.
6. Nitta was also cited by the Examiner as teaching a signal routing
method and apparatus that generates a topologically morphed alternate
signal path of an original signal path, and then selects a replacement path
using the morphed path (Ans. 7).
7. Nitta teaches a signal routing method and apparatus which, for a
signal path (Fig. 12A, t1 to t3) enumerates at least one alternate signal path
(Fig. 12C, t1 to t3) by sliding a plurality of path segments (segments t1 to s1,
s1 to s2, and s2 to t3), wherein the alternate path(s) are topologically
equivalent. Nitta also teaches a morphed version of the original signal path
(Fig. 12B, dotted line segment starting from s12 and extending down). Nitta
teaches that the number of segments in the path (t1 to t3) remains the same
in Nitta as between the original path (Fig. 12A) and the alternate path(s)
(Figs. 12B and 12C).

PRINCIPLES OF LAW
Analysis of whether a claim is patentable over the prior art under 35
U.S.C. § 102 begins with a determination of the scope of the claim. “During
examination, ‘claims … are to be given their broadest reasonable
interpretation consistent with the specification, and … claim language
should be read in light of the specification as it would be interpreted by one
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of ordinary skill in the art.” In re Am. Acad. of Sci. Tech Ctr., 367 F.3d
1359, 1364 (Fed. Cir. 2004); Phillips v. AWH Corp., 415 F.3d 1303, 1313
(Fed. Cir. 2005) (en banc); In re Morris, 127 F.3d 1048, 1054 (Fed. Cir.
1997). In interpreting the meaning of claim terms, “[d]ifferences among
claims can also be a useful guide in understanding the meaning of particular
claim terms. Phillips, 415 F.3d at 1314 (citations omitted). "[T]he presence
of a dependent claim that adds a particular limitation gives rise to a
presumption that the limitation in question is not present in the independent
claim." Id. at 1315 (citations omitted).
Anticipation is established when a single prior art reference discloses
expressly or under the principles of inherency each and every limitation of
the claimed invention. Atlas Powder Co. v. IRECO, Inc., 190 F.3d 1342,
1347 (Fed. Cir. 1999); In re Paulsen, 30 F.3d 1475, 1478-79 (Fed. Cir.
1994). “A claim is anticipated only if each and every element as set forth in
the claim is found, either expressly or inherently described, in a single prior
art reference.” Verdegaal Bros. Inc., v. Union Oil Co. of Calif., 814 F.2d
628, 631 (Fed. Cir. 1987).

ANALYSIS
Issue 1: Does Nitta Teach Enumeration of a Topological Equivalent Signal
Path By Sliding As Recited in Claim 1 on Appeal?

Appellant contends that Nitta does not teach the “enumeration” by
sliding to generate a “topological equivalent” replacement path for an
original signal path (App. Br. 5-7). Appellant relies upon the description of
“topological equivalent” at pages 7 to 8 of the Specification (App. Br. 5).
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We note that claim terms should be given their broadest reasonable
meaning in their ordinary usage as such claim terms would be understood by
one skilled in the art by way of definitions and the written description.
Morris, 127 F.3d at 1054. In this case, we find that the term “topological
equivalent” signal paths would be understood by one of ordinary skill in the
art to mean “two topologically equivalent signal paths” having “the same
number of path segments” with “the corresponding path segments …
necessarily parallel to one another (similarly oriented)” (Finding of Fact 2).
In our view, Figures 12A through C and the accompanying text of Nitta
teach exactly this.
We do not agree with Appellant that the language of claim 1 requires
an analysis of Nitta’s path to be from start point s1 to end point s2 instead of
from t1 to t3 as asserted by the Examiner. In our view, claim 1 broadly calls
for “a signal path of a circuit design.” Claim 1 does not require a particular
starting or ending point for an individual path or segment, thus Appellant’s
arguments drawn toward whether or not Nitta’s Correction Rules 1 and 2
using various start and end points as listed in Figure 10 are not persuasive
(Reply Br. 2-7). We conclude that one of ordinary skill in the art would
consider Nitta as teaching many possible signal paths, including a signal
path from t1 to t3 (Nitta, Figs. 12A-C), and thus understand that an original
signal path (having 3 segments: t1 to s1, s1 to s2, and s2 to t3) is slid (Nitta,
Fig. 12B) in order to enumerate and select a replacement path (Nitta, Fig.
12C) that is “topologically equivalent” (note that the replacement path has
the same number of segments, three, as does the original path, and that it is
similarly oriented). Although the replacement path of Nitta in Figure 12C
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has certain segments which are longer than those of the original path, neither
claim 1 nor the written description requires length to be a factor in
determining topological equivalency (see Spec. 7-8).
With respect to whether or not Nitta enumerates “by sliding” (App.
Br. 6-7; Reply Br. 7-8), we are not persuaded by Appellant’s arguments that
Nitta does not teach “any ‘sliding’ of the segments” (Reply Br. 7), and that
“Nitta fails to teach sliding of the path segment with respect to either
correction rule 1 or correction rule 2” (Reply Br. 8). As discussed above, it
is our view that claim 1 does not require the use of correction rules 1 and 2,
nor does it require the signal path start at point s1 and end at point s2. In
short, we agree with the Examiner that Nitta teaches the features of claim 1
(Finding of Fact 5).
With respect to Appellant’s arguments that Nitta does not teach
“maintaining the topology correspondence between the original and the
alternate signal routes” (App. Br. 5-6), and that “Nitta fails to teach an
equivalent topology” (Reply Br. 7), we are not persuaded by these
arguments since they are based on restricting Nitta’s teachings to a path
starting at point s1 and ending at point s2. Although we agree with
Appellant that an enumeration of the path from s1 to s2 would result in an
alternate path having a different number of segments, and therefore produce
an alternate path which is not a topological equivalent to the original signal
path, in our view claim 1 is not limited to a particular signal path and is met
by Nitta’s original path and alternate paths t1 to t3 in Figures 12A through C
as discussed supra. Accordingly, we agree with the Examiner’s analysis on
this issue (Ans. 5-6; see also Finding of Fact 7).
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With respect to whether or not Nitta enumerates one or more alternate
paths that are topologically equivalent (see App. Br. 6; Reply Br. 8-9), we
are not persuaded by Appellant’s arguments that Nitta does not teach
“enumeration” based on plural candidate paths, since claim 1 broadly calls
for “one or more” alternate paths. Nitta enumerates at least one alternate
path (see Fig. 12C, final path from t1 to t3). Nevertheless, we note that Nitta
teaches two possible alternate paths (see Fig. 12B, path t1 to t3 going
through s11 to s2, and path t1 to t3 going through s11, s12, and s2).

Issue 2: Does Nitta Teach Generating a Topologically “Morphed” Version
of a Signal Path As Recited in Claim 9 on Appeal?

Appellant contends that Nitta’s Figure 12C is not a replacement path
for an “intermediate” path that is derived by morphing the original path as
shown in Nitta’s Figure 12A (App. Br. 7, Reply Br. 9-10). Appellant
contends that any analysis of the “signal path” of claim 9 as starting from t1
and ending at t3 is flawed for the same reasons as just discussed above with
respect to Appellant’s arguments regarding claim 1 (Reply Br. 10).
Appellant also contends that “[n]owhere does Nitta disclose breaking a
segment into two portions and sliding them in opposite directions” (Reply
Br. 10). We note that the language of claim 9 fails to use the term
“intermediate” or the term “opposite;” nor does claim 9 describe how a
“morphed version” of the signal path is to be obtained.
We agree with the Examiner that Nitta’s Figure 12B shows a first
dotted line starting at point s12 which is a “‘first topologically morphed
version of a signal path’” (Ans. 7; Finding of Fact 6). In addition, we note
that the majority of Appellant’s arguments with respect to claim 9 are drawn
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to the details of the Specification (see Finding of Fact 3 for the
Specification’s detailed description of topology morphing) and the claim
language of claim 10 (see claim 10 which further defines the generation of
the first topologically morphed version of the signal path as including
“sliding the first and second portions … in opposite direction”),5 and not
representative claim 9 (see App. Br. 7; Reply Br. 9-10).
Our analysis of the meaning of the language of claim 9 includes
consideration of the doctrine of claim differentiation as recently applied by
our reviewing court, the Court of Appeals for the Federal Circuit. See
Saunders Group, Inc. v. Comfortrac, Inc., 492 F.3d, 1326, 1331 (Fed. Cir.
2007) (stating that where a dependent claim adds a limitation to an
independent claim, the doctrine of claim differentiation supports the

5 Claim 10 reads as follows:
10. The signal routing method of claim 9, wherein said generating of the first
topologically morphed version of the signal path comprises
selecting a first path segment of the signal path;
selecting a point on the first path segment to break the first path
segment into a first and a second portion;
sliding the first and second portions of the first path segment in
opposite directions by a first and a second offset amount respectively, the
opposite directions being substantially orthogonal to an orientation of the
first path segment; and
inserting a bridge portion to connect the first and the second portion of
the first path segment.

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inference that the independent claim encompasses subject matter which does
not include the added limitation). Under the doctrine of claim
differentiation, we look to differences between claims to determine the
meaning of claim language. See Phillips, 415 F.3d at 1314-15 (“[T]he
presence of a dependent claim that adds a particular limitation gives rise to a
presumption that the limitation in question is not present in the independent
claim.”). In this case, we note that dependent claim 10, which depends from
independent claim 9, recites and expands upon the morphing process of
claim 9 (i.e., dependent claim 10 adds the limitation, inter alia, of sliding
path segments in opposite directions). Claim 9 broadly calls for generating a
“topologically morphed version of a signal path” (see claim 9 on appeal),
while claim 10 sets forth the details of the morphing process as including
breaking a path segment and then sliding the broken portions “in opposite
directions.” (See claim 10 on appeal supra note 5). Thus, the doctrine of
claim differentiation supports the inference that the details of dependent
claim 10 of generating a topologically morphed version of a signal path by
breaking a path segment and then sliding path segments in opposite
directions are not necessarily encompassed by independent claim 9 which
does not recite these details. See Saunders Group, Inc., 492 F.3d at 1331.
We note that Appellant’s Specification describes morphing as
involving breaking a signal path into segments and then sliding the segments
away from each other in opposite directions (Spec. 9-10), and this is recited
positively in claim 10. We also note that we must be careful not to read a
particular embodiment appearing in the written description into the claim if
the claim language is broader than the embodiment. See Superguide Corp.
v. DirecTV Enters., Inc., 358 F.3d 870, 875 (Fed. Cir. 2004) (“Though
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understanding the claim language may be aided by explanations contained in
the written description, it is important not to import into a claim limitations
that are not part of the claim. For example, a particular embodiment
appearing in the written description may not be read into a claim when the
claim language is broader than the embodiment.”) The challenge is to
interpret claims in view of the specification without unnecessarily importing
limitations from the specification into the claims. See E-Pass Techs., Inc. v.
3Com Corp., 343 F.3d 1364, 1369 (Fed. Cir. 2003).
In our view, claim 9 recites morphing in a much broader fashion and
thus does not require the details of claim 10, and thus claim 9 reads on many
other types of topological morphing including sliding or moving segments in
directions other than “opposite.” See Phillips, 415 F.3d at 1315 (stating that
presence of dependent claim adding particular limitation gives rise to
presumption that limitation in question is not present in independent claim).
Accordingly, Appellant’s arguments regarding the requirement that
“morphing” include sliding path segments in opposite directions is
unpersuasive with respect to representative claim 9. Appellant has not
convinced us that the Examiner erred in rejecting claim 9 as being
anticipated by the teachings of Nitta. Likewise, Appellant’s argument that
“any analysis based on the signal path originating from t1 and ending at t3,
while focusing on the figures 12A-C is inherently flawed” (Reply Br. 10), is
unpersuasive since we conclude that claim 9 does not require a particular
starting and/or end point, and merely calls for “a signal path of a circuit
design.”
We have considered all the arguments, including those in the Reply
Brief filed on May 22, 2007, but find them unpersuasive for reasons given
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above. Cf. Hartman v. Nicholson, 483 F.3d 1311, 1315 (Fed. Cir. 2007) (all
remaining arguments were considered, but none were found that warrant
reversal).
In summary, all of the limitations of claims 1 and 9 on appeal are
found, either expressly or inherently, in the teachings of Nitta. Accordingly,
we will sustain the Examiner’s rejection of those claims, and claims 2 to 8
and 10 to 29 which fall with claims 1 and 9.

CONCLUSION OF LAW
For the foregoing reasons, Appellant has not shown that the Examiner
erred in rejecting claims 1 to 29 over the disclosure to Nitta under § 102.

ORDER
The anticipation rejection of claims 1 to 29 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

KIS

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