IP Library › Granted Patent US 8,773,167
Granted Patent B2
US 8,773,167 · App. 13/561,978 · Granted Jul 8, 2014

Implementing logic circuits with memristors

Inventors: Warren Robinett (Chapel Hill, NC); R. Stanley Williams (Portola Valley, CA)
Assignee: Hewlett-Packard Development Company, L.P.
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Quick Facts
Patent No.
US 8,773,167
App. No.
13/561,978
Filed
Jul 30, 2012
Granted
Jul 8, 2014
Kind
B2
Examiner
TAN, VIBOL
Art Unit
2844
USPC
326/38
Abstract

Implementing logic with memristors may include circuitry with at least three memristors and a bias resistor in a logic cell. One of the at least three memristors is an output memristor within the logic cell and the other memristors of the at least three memristors are input memristors. Each of the at least three memristors and the bias resistor are electrically connected to voltage sources wherein each voltage applied to each of the at least three memristors and the bias resistor and resistance states of the at least three memristors determine a resistance state of the output memristor.

Claims (33)

1. A device for implementing logic with memristors, comprising:

circuitry comprising at least three memristors and a bias resistor in a logic cell;

one of said at least three memristors being an output memristor within said logic cell and other memristors of said at least three memristors are input memristors; and

each of said at least three memristors and said bias resistor are electrically connected to voltage sources, wherein each voltage applied to each of said at least three memristors and said bias resistor and resistance states of said at least three memristors determine a resistance state of said output memristor.

2. The device of claim 1 , wherein said logic cell implements any one of: a NAND gate, AND gate, NOR gate, OR gate, NOT gate, XOR gate, a MAJ gate, full adder, or combinations thereof.

3. The device of claim 1 , wherein an voltage drop V c -V out is applied to said output memristor substantially according to V c =(Σ(G i )(V i ))/ΣG i , where V c is a voltage of a central node of the logic cell, G i is input conductances of said at least three memristors and said bias resistor, and V i is a voltage applied to said at least three memristors and said bias resistor.

4. The device of claim 1 , wherein said circuitry is arranged in a cross bar array.

5. The device of claim 1 , wherein said bias resistor and said voltages are adjustable from a first phase to a second phase.

6. The device of claim 1 , said at least three memristors comprise at least one of: niobium, titanium, tungsten, manganese, iron, vanadium, indium, silicon, tantalum, hafnium, nickel, aluminum, zirconium, molybdenum, copper, chromium, silver, oxides thereof, nitrides thereof, carbides thereof, phosphides thereof, sulfides thereof, doped alloys thereof, single element metals, semiconductors, or combinations thereof.

7. The device of claim 1 , wherein said bias resistor is another memristor.

8. A circuit for implementing logic with memristors, comprising:

at least two memristors and a capacitor in a logic cell;

one of said at least two memristors is an output memristor within said logic cell and remaining memristors of said at least two memristors are input memristors; and

each of said at least two memristors and said capacitor are electrically connected to voltage sources, wherein each voltage applied to each of said at least two memristors and said capacitor determine a resistance state of said output memristor where said resistance state of said output memristor is a function of resistance states of said input memristors.

9. The device of claim 8 , wherein said input memristors are connected in parallel to said capacitor, wherein said capacitor is positioned to sum charges of signals passed through said input memristors with a voltage across said capacitor representing said sum of charges used to determined resistance states of said output memristor.

10. The device of claim 8 , wherein said voltage sources are time varying voltage sources that act as control signals.

11. The device of claim 8 , wherein said logic cell implements any one of: a NAND gate, AND gate, NOR gate, OR gate, NOT gate, XOR gate, a MAJ gate, full adder, or combinations thereof.

12. A device with memristor implemented logic, comprising:

circuitry comprising a memristor array arranged as a digital look-up table;

a set of memristors acting as a demultiplexer arranged to route a signal to at least one selected memristor in a look-up table of said memristor array, in which said selected memristor is specified with a set of at least one input memristor acting as an address of said selected memristor within said look-up table; and

at least one output memristor electrically connected to said memristor array;

wherein a resistance state of said selected memristors is copied to said output memristors.

13. The device of claim 12 , wherein said look-up table comprises dimensions of (2 k )(j), where k represents a length of a binary bit input vector and j represents a length of a binary bit output vector.

14. The device of claim 12 , wherein said memristor array, said set of memristors, and said output memristor are arranged in a cross bar array.

15. The device of claim 12 , wherein at least two memristors in which said set of memristors form a bi-directional analog multiplexer.

16. A device with a memristor based bi-directional analog multiplexer, comprising:

a set of at least two bistable routing memristors;

a set of one or more control memristors comprising resistance states to determine that whether a state of each of the set of at least two bistable routing memristors is an on state or an off state; and

one source wire and two or more destination wires, in which states of the control memristors determine which of the destination wires are electrically connected to the source wire.

17. The device of claim 16 , wherein the bi-direction analog multiplexer comprises one of: a demultiplexer or a multiplexer.

18. The device of claim 16 , wherein said set is positioned along a pathway between a voltage source connected to the source wire and multiple routing-target locations connected to the two or more destination wires.

19. The device of claim 18 , wherein said multiple routing-target locations are locations within a look-up table, in which the one source wire and two or more destination wires are wires within a crossbar array and the bistable routing memristors and control memristors are crosspoint devices within the crossbar array.

20. The device of claim 18 , wherein resistance states of said set of at least two bistable routing memristors determine to which routing-target location a signal from a voltage source connected to the source wire is sent.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 9, 2015
From: HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P.
To: HEWLETT PACKARD ENTERPRISE DEVELOPMENT LP
Reel/Frame 037079/0001 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 31, 2012
From: ROBINETT, WARREN; WILLIAMS, R. STANLEY
To: HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P.
Reel/Frame 028688/0280 →
Continuity (1)
Related Publication 20140028347A1 · Jan 30, 2014