Electronic digital logic circuitry – Interface – Current driving
Reexamination Certificate
1998-12-18
2001-01-30
Tokar, Michael (Department: 2819)
Electronic digital logic circuitry
Interface
Current driving
C326S083000
Reexamination Certificate
active
06181167
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for the simultaneous transmission of two data signals over the same line in opposite directions.
2. Description of the Prior Art
The most common method of allowing two electronic modules to communicate with each other via simultaneous bi-directional (full duplex) data flow is by connecting them together with two electrical lines, one for data transmission in each direction. In an effort to reduce the number of electrical lines connecting electronic devices, and consequently the number of pins or terminals on an electronic device devoted to this communication, technology has been developed to allow for the transmission of two data sequences in opposite directions over the same communication line.
Two ways of doing this are frequency multiplexing, and time multiplexing. Frequency multiplexing is not at all useful when dealing with standard logic levels within a circuit, and time multiplexing is inherently slow, due to the fact that you can only send one signal in one direction at a time.
To overcome these problems, technology has been developed to allow two electrical circuits to communicate with each other over a single electrical interconnect in both directions at the same time. Past technology for doing this has been slow in terms of switching rate, required considerable power consumption, and/or required impedance matching with the transmission line, all of which are not desirable.
It is an object of the present invention to provide a means for simultaneous full duplex communication over a single electrical interconnect at standard CMOS logic levels and thresholds.
It is also an object of the present invention to provide this communication without making speed power ratio sacrifices, or requiring a matched line impedance.
BRIEF SUMMARY OF THE INVENTION
The present invention solves these and other needs by providing a CMOS circuit which will allow two electronic modules to communicate individual data in each direction simultaneously over a single line without compromising the speed power ratio. This is accomplished by providing two transceivers on opposite ends of an electrical interconnect. The first transceiver consists of a voltage driver with a resistive load between the voltage driver's output and the input/output terminal of the first transceiver. Across this resistive load is placed a current sensing circuit. This current sensor acts as the receiver portion of the first transceiver. The second transceiver consists of a voltage receiver with its input connected to the input/output terminal of the second transceiver. Also connected to this input/output terminal of the second transceiver are the send logic high and send logic low circuit blocks which function as the transmitter portion of the second transceiver by allowing current to flow when they are on.
REFERENCES:
patent: 4859877 (1989-08-01), Cooperman et al.
patent: 5801549 (1998-09-01), Cao et al.
Fredrick Kris T.
Honeywell Inc.
Tokar Michael
Tran Anh
LandOfFree
Full duplex CMOS communication does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Full duplex CMOS communication, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Full duplex CMOS communication will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2554499