Ex parte AMINI et al.

Board of Patent Appeals and Interferences

Jun 29, 1998

07962425 (B.P.A.I. Jun. 29, 1998)

Application for patent filed October 16, 1992. 1
As indicated in the Advisory Action (paper number 8), the2
amendment to claims 1 and 6 had the effect of overcoming the
indefiniteness rejection of claims 1, 3 through 6 and 8
through 10.
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered
today (1) was not written for publication in a law
journal and (2) is not binding precedent of the Board.
Paper No. 14
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte ISMAEL Z. AMINI, TZE-WING KEUNG and
ANDRES M. MOLINA
____________
Appeal No. 95-4913
Application No. 07/962,4251
____________
ON BRIEF
____________
Before HAIRSTON, BARRETT and FLEMING , Administrative Patent
Judges.
HAIRSTON, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal from the final rejection of claims 1, 3
through 6 and 8 through 10. In an Amendment After Final (paper2
number 7), claims 1 and 6 were amended.
Appeal No. 95-4913
Application No. 07/962,425
2
As indicated by the title, the disclosed invention relates
to a method and system for reduced metastability between devices
which communicate and operate at different clock frequencies.
Claim 1 is illustrative of the claimed invention, and it
reads as follows:
1. A method in a data processing system having a first
clock operating at a first clock rate and a second clock
operating at a second clock rate for improving communication
between a first device associated with said first clock rate and
a second device associated with said second clock rate, said
method comprising within said data processing system the steps
of:
determining particular periods of time during which
metastability may occur as a result of data being transmitted
from said first device at said first clock rate and received by
said second device at said second clock rate;
continually processing said data by double latching said
data transmitted from said first device to said second device;
during said particular periods of time, inputting said
processed data into said second device; and
during all other periods of time, inputting said data
directly into said second device.
The references relied on by the examiner are:
Heckel 4,176,400 Nov. 27, 1979
Flemming 4,405,898 Sep. 20, 1983
Azevedo et al. (Azevedo) 4,868,514 Sep. 19, 1989
Claims 1, 3 through 6 and 8 through 10 stand rejected under
35 U.S.C. § 103 as being unpatentable over the admitted prior art
(specification, pages 2 and 3) in view of Flemming and Heckel.
Appeal No. 95-4913
Application No. 07/962,425
3
Claims 5 and 10 stand rejected under 35 U.S.C. § 103 as
being unpatentable over the admitted prior art in view of
Flemming, Heckel and Azevedo.
Reference is made to the brief and the answer for the
respective positions of the appellants and the examiner.
OPINION
We have carefully considered the entire record before us,
and we will reverse the obviousness rejection of claims 1, 3
through 6 and 8 through 10.
In the admitted prior art (specification, page 3), the
solution for “avoiding metastability has been to double latch all
data input into the receiving device” during all periods of time.
Flemming also avoids the metastability problem by altering one of
the clock outputs from the single clock generating source 42
(Figure 5) with a phase lock loop circuit (Figure 6). We agree
with the examiner (Answer, page 5) that “Heckel discloses means
for inputting data directly.” On the other hand, we agree with
appellants (Brief, pages 5 and 6) that:
Heckel describes a one-clock system. The problems
which Applicants desire to solve arise only in a system
having two asynchronous clocks. Applicants[’] method
and system are directed to solving metastability
problems. Heckel does not discuss metastability
problems or solutions to these problems. Heckel
describes a buffering system used when transmitting
Appeal No. 95-4913
Application No. 07/962,425
4
data from a teletype to a printing device. Heckel
describes routing data from an input latch to an output
latch when the data includes repeating characters. At
other times, data is routed from an input latch,
through a shift register, and then to the output latch.
All devices in Heckel are clocked at the same clock
frequency.
Appellants have correctly concluded (Brief, page 6) that
“[e]ven if Heckel is combined with Flemming, the combination does
not describe Applicants[’] method and system,” especially
“determining particular periods of time during which
metastability may occur” (claims 1 and 6).
Azevedo teaches digital compensation of oscillator drift by
providing phase alignment between two clock signals. We agree
with appellants (Brief, page 8) that Flemming, Heckel and Azevedo
neither teach nor would they have suggested to one of ordinary
skill in the art “the claimed elements.”
In summary, the obviousness rejection of claims 1, 3 through
6 and 8 through 10 is reversed.
Appeal No. 95-4913
Application No. 07/962,425
5
DECISION
The decision of the examiner rejecting claims 1, 3 through 6
and 8 through 10 under 35 U.S.C. § 103 is reversed.
REVERSED
KENNETH W. HAIRSTON )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
LEE E. BARRETT ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
MICHAEL R. FLEMING )
Administrative Patent Judge )
Appeal No. 95-4913
Application No. 07/962,425
6
Andrew J. Dillon
FELSMAN, BRADLEY, GUNTER & DILLON
2600 Continental Plaza
777 Main Street
Fort Worth, TX 76102
KWH/jrg
JENINE GILLIS
Appeal No. 95-4913
Serial No. 07/962,425
Judge HAIRSTON

Judge BARRETT
Judge FLEMING
Received: 18 Jun 98
Typed: 18 Jun 98
DECISION: REVERSED
Send Reference(s): Yes No
or Translation(s)
Panel Change: Yes No
3-Person Conf. Yes No
Heard: Yes No
Remanded: Yes No
Index Sheet-2901 Rejection(s): ___________
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