Transmission-reception circuit
AssigneeHitachi, Ltd.
InventorRyozo Yoshino
Life of this patent
Estimating the term…
Abstract
A transmission-reception circuit, including a transmitter circuit and a receiver circuit connected to each end of a transmission line, for transmitting and receiving a signal to another receiver circuit and from another transmitter circuit at the other end across the transmission line, wherein in order to enable logical decision on a receiving signal to be made accurately and secure high reliability in a fully duplex simultaneous two-way communication, power supply lines are laid at opposite ends of the transmission line and threshold voltages for logical decision on a signal received by the receiver circuit are supplied from a power unit used for the transmitter circuit and the receiver circuit at the other end of the transmission line.
Claims7
A transmission-reception apparatus, including a first transmission-reception circuit connected to one end of a single transmission line, and a second transmission-reception circuit connected to the other end of the transmission line, for transmitting and receiving a signal over said transmission line between said first transmission-reception circuit and said second transmission-reception circuit, wherein
- said first transmission-reception circuit includes a first transmitter circuit connected to said transmission line for transmitting a signal to, said second transmission-reception circuit, and a first receiver circuit connected to said transmission line for receiving a signal from said second transmission-reception circuit;
- said second transmission-reception circuit includes a second transmitter circuit connected to said transmission line for transmitting the signal to said first transmission-reception circuit, and a second receiver circuit connected to said transmission line for receiving the signal from said first transmission-reception circuit;
- a first power unit is disposed in the vicinity of said first transmission:
- reception circuit to supply electric power required for said first transmission-reception circuit;
- a second power unit is disposed in the vicinity of said second transmission-reception circuit to supply electric power required for said second transmission-reception circuit;
- a power supply line includes a first power supply wire connected between said first power unit and said second receiver circuit, and a second power supply wire connected between said second power unit and said first receiver circuit;
- a threshold voltage for logical decision on a receiving signal of said first receiver circuit is supplied from said second power unit through said power supply line;
- and a threshold voltage for logical decision on a receiving signal of said second receiver circuit is supplied from said first power unit through said power supply line.
A transmission-reception apparatus, including at least two transmission-reception circuits connected to a bus-structure type common transmission line, for transmitting and receiving a signal through said common transmission line between said two transmission-reception circuits, wherein
- each of said transmission-reception circuits includes a transmitter circuit connected to said common transmission line for transmitting a signal to the other transmission-reception circuit, and a receiver circuit connected to said common transmission line for receiving a signal from the other transmission-reception circuit;
- each of said receiver circuits comprises
- first comparing means for comparing a signal sent out on said common transmission line with first and second threshold voltages for logical decision on a receiving signal, said first and second threshold voltages differing in voltage level by an amount corresponding to an amplitude of the signal transmitted and received between said two transmission-reception circuits,
- receiving signal outputting means for outputting a signal sent out from the other transmission-reception circuit as a receiving signal by removing a signal which is sent out by the transmission-reception circuit to which said receiver circuit belongs on a basis of a comparison result of said first comparing means and an input signal to said transmitter circuit, and
- second comparing means for comparing the signal sent out on said common transmission line by the transmission-reception circuit to which said receiver circuit belongs with a third threshold voltage of a level further higher by an amount corresponding to an amplitude of said signal sent out on said common transmission line than a sum of the first and second threshold voltages and for outputting a signal to invalidate a signal when the signal having a voltage level exceeding the third threshold voltage appears on said common transmission line.
A transmission-reception system, including a first transmission-reception device connected to one end of a single transmission line and a second transmission-reception device connected to the other end of said transmission line, for transmitting and receiving a signal over said transmission line between said first transmission-reception device and said second transmission-reception device, wherein
- said single transmission line includes n transmission wires, where n is an integer greater than or equal to 1;
- said first transmission-reception device includes n first transmission-reception circuits respectively connected to said n transmission wires;
- said second transmission-reception device includes n second transmission-reception circuits respectively connected to said n transmission wires;
- each of said n first transmission-reception circuits includes a first transmitter circuit connected to corresponding one of said n transmission wires for transmitting a signal to corresponding one of said n second transmission-reception circuits, and a first receiver circuit connected to the corresponding one of said n transmission wires for receiving a signal from the corresponding one of said n second transmission-reception circuits;
- each of said n second transmission-reception circuits includes a second transmitter circuit connected to corresponding one of said n transmission wires for transmitting a signal to corresponding one of said n first transmission-reception circuits, and a second receiver circuit connected to the corresponding one of said n transmission wires for receiving a signal from the corresponding one of said n first transmission-reception circuits;
- said first transmission-reception device includes a first power unit for supplying electric power required for said n second transmission-reception circuits;
- said second transmission-reception device includes a second power unit for supplying electric power required for said n first transmission-reception circuits;
- a power supply line is laid between said first transmission-reception device and said second transmission-reception device;
- said power supply line includes a first power supply wire for connecting said first power unit to said second receiver circuit of each of said n second transmission-reception circuits, and a second power supply wire for connecting said second power unit to said first receiver circuit of each of said n first transmission-reception circuits;
- a threshold voltage for logical decision on a receiving signal of said first receiver circuit of each of said n first transmission-reception circuits is supplied from said second power unit through said power supply line;
- and
- a threshold voltage for logical decision on a receiving signal of said second receiver circuit of each of said n second transmission-reception circuits is supplied from said first power unit through said power supply line.
Dependencies are inferred from the claim text.