Pulse or digital communications – Cable systems and components
Reexamination Certificate
1999-10-15
2002-03-19
Corrielus, Jean (Department: 2631)
Pulse or digital communications
Cable systems and components
C375S286000, C375S316000
Reexamination Certificate
active
06359931
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a multilevel signaling system for transmitting signals across a multiconductor transmission line.
BACKGROUND OF THE INVENTION
Various techniques and systems are available for transmitting data between a source and a destination. When data is electrically transmitted across a conductor, a particular signaling technology or protocol is utilized. A set of symbols may be associated with specific signaling technologies. The symbols are used to encode the data into various electrical patterns on the transmission line conductors such that each symbol may be distinguished from other signals by analyzing the electrical pattern on the conductors. The conductors used to transmit data include wires, cables, traces on printed circuit boards, conductors embedded within a substrate, and various other conductive materials.
In certain data transmission systems, the conductors are treated as transmission lines and analyzed by considering various electrical and electromagnetic wave properties and characteristics. In these systems, the signaling technology may include the coupling of signal drivers, signal receivers, conductors, and termination devices.
A particular type of data transmission system transmits signals differentially. For example,
FIG. 1
illustrates a known differential transmission system using a pair of conductors. A differential driver
10
receives data on input
12
and transmits differential signals across conductors
14
and
16
. Conductor
14
is coupled to the non-inverting output of driver
10
and conductor
16
is coupled to the inverting output of driver
10
. A differential receiver
18
(also referred to as a differential comparator) receives the differential signals from conductors
14
and
16
, and generates an output on line
20
. Conductor
14
is coupled to the non-inverting input of receiver
18
and conductor
16
is coupled to the inverting input of receiver
18
. A pair of terminating resistors
22
,
24
are coupled between conductors
14
and
16
, and a terminating voltage V
term
.
In the system of
FIG. 1
, the pair of conductors
14
,
16
are capable
10
of transmitting two symbols representing a binary zero or binary one. The data provided to driver
10
represents one of two possible symbols; e.g., a binary zero or one. Driver
10
transmits a particular signal pattern on conductors
14
,
16
based on the input data provided to the driver. For example, when a binary zero is the input data, driver
10
generates a logic low signal on its non-inverting output which is coupled to conductor
14
. Driver
10
also generates a logic high signal on its inverting output which is coupled to conductor
16
. Conversely, when a binary one is the input data, driver
10
generates a logic high signal on its non-inverting output and generates a logic low signal on its inverting output. Thus, the polarity of the outputs from differential driver
10
are always opposite one another. The output polarity is controlled by the input signal applied to driver
10
.
Differential driver
10
may be a current mode driver which produces output currents (i
0
and i
1
) in response to the input provided. The value of v
0
is defined as v
0
=V
term
−i
0
R
t
. Similarly, the value of v
1
is defined as v
1
=V
term
−i
1
R
t
. Receiver
18
compares the voltage levels on its two inputs and generates the data output signal corresponding to the input provided to driver
10
.
The differential signaling system illustrated in
FIG. 1
requires two conductors
14
,
16
to transmit a single bit of data. Therefore, this method results in an inefficient use of data interconnect resources (number of conductors=2×number of bits transmitted). Certain applications may require a more efficient use of interconnect resources in a differential transmission system. Thus, it is desirable to provide a system having the advantages provided by differential signaling, but without the inefficient ratio of the number of conductors to the number of bits transmitted.
SUMMARY OF THE INVENTION
The present invention provides a multilevel signaling system using multiple conductors for transmitting data from a source to a destination.
An embodiment of the present invention includes at least three conductors coupled between the transmission source and the transmission destination. Multiple drivers are coupled to the conductors at the transmission source. Multiple comparators are coupled to the conductors at the transmission destination. Each comparator is coupled to a pair of conductors.
Another feature of the invention provides that the drivers maintain a constant current on the multiple conductors. The constant current is maintained for all signal patterns transmitted along the conductors.
Each signal pattern generates a linear combination of eigenvectors. A particular embodiment of the invention utilizes linear combinations of equal speed eigenvectors.
Another aspect of the invention includes a first translator coupled to the drivers. The first translator generates control signals for controlling the drivers.
Additionally, a second translator may be coupled to the comparators. The second translator generates an output signal in response to the signals generated by the comparators.
A specific feature of the invention couples multiple comparator inputs such that an “n choose two” combinatorial matrix is generated.
A specific embodiment of the invention provides a substantially symmetrical arrangement of the multiple conductors.
REFERENCES:
patent: 3671671 (1972-06-01), Watanabe
patent: 3731199 (1973-05-01), Tazaki et al.
patent: 3753113 (1973-08-01), Maruta et al.
patent: 3754237 (1973-08-01), de Laage de Meux
patent: 3772680 (1973-11-01), Kawai et al.
patent: 3835252 (1974-09-01), Ananiades et al.
patent: 3943284 (1976-03-01), Nelson
patent: 3983323 (1976-09-01), Griffith et al.
patent: 4070650 (1978-01-01), Ohashi et al.
patent: 4084069 (1978-04-01), Looschen
patent: RE30182 (1979-12-01), Howson
patent: 4280221 (1981-07-01), Chun et al.
patent: 4373152 (1983-02-01), Jacobsthal
patent: 4382249 (1983-05-01), Jacobsthal
patent: 4408135 (1983-10-01), Yuyama et al.
patent: 4408189 (1983-10-01), Betts et al.
patent: 4489417 (1984-12-01), Askin et al.
patent: 4498166 (1985-02-01), Esposito
patent: 4525845 (1985-07-01), Dodds et al.
patent: 4528550 (1985-07-01), Graves et al.
patent: 4571735 (1986-02-01), Furse
patent: 4581691 (1986-04-01), Hock
patent: 4606046 (1986-08-01), Ludwick
patent: 4631428 (1986-12-01), Grimes
patent: 4805190 (1989-02-01), Jaffre′ et al.
patent: 4825450 (1989-04-01), Herzog
patent: 4875049 (1989-10-01), Yoshida
patent: 4910750 (1990-03-01), Fisher
patent: 5034964 (1991-07-01), Khan et al.
patent: 5160929 (1992-11-01), Costello
patent: 5166956 (1992-11-01), Baltus et al.
patent: 5172338 (1992-12-01), Mehrotra et al.
patent: 5191330 (1993-03-01), Fisher et al.
patent: 5235617 (1993-08-01), Mallard, Jr.
patent: 5255287 (1993-10-01), Davies et al.
patent: 5259002 (1993-11-01), Charlstedt
patent: 5341419 (1994-08-01), Ferry
patent: 5377231 (1994-12-01), Sonntag
patent: 5412689 (1995-05-01), Chan et al.
patent: 5418504 (1995-05-01), Nottenburg
patent: 5438593 (1995-08-01), Karam et al.
patent: 5553097 (1996-09-01), Dagher
patent: 5566125 (1996-10-01), Fazio et al.
patent: 5640605 (1997-06-01), Johnson et al.
patent: 5740201 (1998-04-01), Hui
patent: 5761246 (1998-06-01), Cao et al.
patent: 5892466 (1999-04-01), Walker
patent: 5923276 (1999-07-01), Frankeny et al.
patent: 2940140 (1979-03-01), None
patent: 0352869 (1989-07-01), None
patent: 0 352 869 (1990-01-01), None
patent: 0 490 504 (1992-06-01), None
patent: WO 95/31867 (1995-11-01), None
Richard E. Matick, “Transmission Lines for Digital and Communication Networks”, IEEE Press, 1995, pp. 268-269.
International Search Report-Sep. 22, 1998-International Application No.: PCT/US 97/23276.
PCT International Application Published Under PCT—International Publication No.: WO 95/31867, International Publication Date: Nov. 23, 1995.
Scott, “Propag
Dillon John B.
Perino Donald V.
Corrielus Jean
Moniz Jose G.
Rambus Inc.
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