Back to results
US 8,552,759 B2Granted
Programmable logic based on a magnetic diode and applications of same
AssigneeNorthwestern University
InventorsBruce W. Wessels, Nikhil Rangaraju
Life of this patent
Estimating the term…
Abstract
In one aspect, the invention relates to programmable logic that utilizes one or more of magnetic diodes. By changing magnetic fields generated in the magnetic diodes due to input signals, the programmable logic can be changed from one logic gate to another logic gate. The unique feature leads to field reprogrammable logic devices in which simple instructions can be used to construct a whole new set of logic gates.
Claims31
A programmable logic cell, comprising:
- a magnetic diode having a non-magnetic semiconductor layer and a magnetic semiconductor layer disposed on the non-magnetic semiconductor layer, wherein the magnetic diode is configured such that under a forward bias, when a magnetic field applied to the magnetic diode is less than a threshold value, the magnetic diode is in a conductive state in which electric current flows through the magnetic diode, and when the magnetic field applied to the magnetic diode is greater than the threshold value, the magnetic diode is in a resistive state in which the electric current flowing through the magnetic diode is substantially reduced;
- a first input wire for receiving a first input current, and a second input wire for receiving a second input current, wherein the first and second input wires are oriented along a first direction parallel to the magnetic semiconductor layer of the magnetic diode and positioned spaced-apart along a second direction perpendicular to the first direction over the magnetic semiconductor layer of the magnetic diode, such that when either of the first input current and the second input current flows through a respective input wire of the first input wire and the second input wire and no current flows through the other input wire, a magnetic field B generated in the magnetic diode is less than the threshold value, and when both the first input current and the second input current flow through the first input wire and the second input wire, respectively, along the same direction, the magnetic field generated in the magnetic diode is greater than the threshold value;
- and
- an output wire oriented along a third direction perpendicular to the first and second directions and positioned under the non-magnetic semiconductor layer of the magnetic diode for outputting a logic “0” or “1” responsive to the first input current and the second input current.
1 more element
A programmable logic cell, comprising:
- a first magnetic diode having a cathode connected to a first input port for receiving a first input signal and an anode;
- a second magnetic diode having a cathode connected to a second input port for receiving a second input signal and an anode connected to the anode of the first magnetic diode;
- a transistor having a base connected to the anode of the second magnetic diode and a collector connected to an output port for outputting a logic “0” or “1” responsive to the first and second input signals, and an emitter connected to ground;
- a first resistor having a first terminal connected to a voltage source having a positive voltage and a second terminal connected to the anode of the first magnetic diode;
- and
- a second resistor having a first terminal connected to the voltage source and a second terminal connected to the collector of the transistor,
- wherein each magnetic diode is configured such that under a forward bias, when a magnetic field applied to the magnetic diode is less than a threshold value, the magnetic diode is in a conductive state in which electric current flows through the magnetic diode, and when the magnetic field applied to the magnetic diode is greater than the threshold value, the magnetic diode is in a resistive state in which the electric current flowing through the magnetic diode is substantially reduced;
- and
- wherein each of the first input signal and the second input signal is a low voltage for which a corresponding one of the first and second magnetic diodes is forward-biased or a high voltage for which the corresponding one of the first and second magnetic diodes is reverse-biased.
6 more elements
A programmable logic cell, comprising:
- a first diode having a cathode connected to a first input port for receiving a first input signal and an anode;
- a second diode having a cathode connected to a second input port for receiving a second input signal and an anode connected to the anode of the first diode;
- a transistor having a base electrically coupled to the anode of the second diode and a collector connected to an output port for outputting a logic “0” or “1” responsive to the first and second input signals, and an emitter connected to ground;
- a magnetic diode having a cathode and an anode connected to a voltage source having a positive voltage, wherein the magnetic diode is configured such that under a forward bias, when a magnetic field applied to the magnetic diode is less than a threshold value, the magnetic diode is in a conductive state in which electric current flows through the magnetic diode, and when the magnetic field applied to the magnetic diode is greater than the threshold value, the magnetic diode is in a resistive state in which the electric current flowing through the magnetic diode is substantially reduced;
- a first resistor having a first terminal and a second terminal connected to the anode of the first diode;
- and
- a second resistor having a first terminal and a second terminal connected to the collector of the transistor,
- wherein the first terminal of one of the first and second resistors is connected to the cathode of the magnetic diode and the first terminal of the other of the first and second resistors is connected to the voltage source;
- and
- wherein each of the first input signal and the second input signal is a low voltage for which a corresponding one of the first and second diodes is forward-biased or a high voltage for which the corresponding one of the first and second diodes is reverse-biased.
7 more elements
A programmable logic cell, comprising:
- a multi-emitter transistor having a base, three emitters connected respectively to a first input port for receiving a first input signal, a second input port for receiving a second input signal and an operation control port for receiving a control signal, and a collector, wherein the multi-emitter transistor comprises a bipolar magnetic junction transistor having a magnetic diode configured such that under a forward bias, when a magnetic field applied to the magnetic diode responsive to the control signal is less than a threshold value, the magnetic diode is in a conductive state in which electric current flows through the magnetic diode, and when the magnetic field applied to the magnetic diode is greater than the threshold value, the magnetic diode is in a resistive state in which the electric current flowing through the magnetic diode is substantially reduced;
- a first resistor having a first terminal connected to a voltage source having a positive voltage and a second terminal connected to the base of the multi-emitter transistor;
- a second resistor having a first terminal connected to the voltage source and a second terminal;
- and
- a first transistor having a base connected to the collector of the multi-emitter transistor, a collector connected to the second terminal of the second resistor and electrically coupled to an output port for outputting logic “0” or “1” responsive to the first and second input signals and the control signal, and an emitter electrically coupled to ground.
2 more elements
Dependencies are inferred from the claim text.