Area efficient neuromorphic system that connects a FET in a diode configuration, and a variable resistance material to junctions of neuron circuit blocks

• US 8,589,320 B2
• Filed: 07/13/2012
• Issued: 11/19/2013
• Est. Priority Date: 11/18/2009
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Breitwisch, Matthew J., Lam, Chung Hon, Modha, Dharmendra S., Rajendran, Bipin
• Primary Examiner(s): VINCENT, DAVID ROBERT
• Application Number:
  US13/548,532
• Publication Number:
  US 20120284217A1
• Time in Patent Office: 494 Days
• Field of Search: 706/12, 706/15, 706/45, 706/62
• US Class Current: 706/15
• CPC Class Codes: G06N 3/065 Analogue means
• CPC Class Codes: G11C 11/54 using elements simulating biological cells, e.g. neuron
• CPC Class Codes: G11C 13/0002 using resistive RAM [RRAM] elements
• CPC Class Codes: H10K 19/202 Integrated devices comprising a common active layer

Abstract

A neuromorphic system includes a plurality of synapse blocks electrically connected to a plurality of neuron circuit blocks. The plurality of synapse blocks includes a plurality of neuromorphic circuits. Each neuromorphic circuit includes a field effect transistor in a diode configuration electrically connected to variable resistance material, where the variable resistance material provides a programmable resistance value. Each neuromorphic circuit also includes a first junction electrically connected to the variable resistance material and an output of one or more of the neuron circuit blocks, and a second junction electrically connected to the field effect transistor and an input of one or more of the neuron circuit blocks.

Claims

1. A neuromorphic system comprising:

a plurality of synapse blocks electrically connected to a plurality of neuron circuit blocks, the plurality of synapse blocks comprising a plurality of neuromorphic circuits arranged in a crossbar configuration, each neuromorphic circuit comprising;

a field effect transistor in a diode configuration electrically connected to variable resistance material, the variable resistance material providing a programmable resistance value;

a first junction electrically connected to the variable resistance material and an output of one or more of the neuron circuit blocks; and

a second junction electrically connected to the field effect transistor and an input of one or more of the neuron circuit blocks.

2. The neuromorphic system of claim 1 wherein the plurality of neuron circuit blocks are further comprised of axons to output signals and dendrites to receive signals, the axons and dendrites positioned at common locations across each of the neuron circuit blocks.

3. The neuromorphic system of claim 2 wherein the plurality of neuron circuit blocks are oriented at an angle relative to the plurality of synapse blocks.

4. The neuromorphic system of claim 1 wherein at least one of the synapse blocks is embedded within at least one of the neuron circuit blocks.

5. The neuromorphic system of claim 1 wherein four or more of the synapse blocks are adjacent to at least one of the neuron circuit blocks in a planar tile configuration.

6. The neuromorphic system of claim 1 wherein the synapse blocks are staggered such that a positional shift of at least one horizontal or vertical connection point occurs between adjacent synapse blocks.

7. A method for implementing an area efficient neuromorphic system, comprising:

electrically connecting a plurality of synapse blocks to a plurality of neuron circuit blocks, the plurality of synapse blocks comprising a plurality of neuromorphic circuits, each neuromorphic circuit implemented by;

electrically connecting a field effect transistor in a diode configuration to variable resistance material, the variable resistance material providing a programmable resistance value;

electrically connecting a first junction to the variable resistance material and an output of one or more of the neuron circuit blocks; and

electrically connecting a second junction to the field effect transistor and an input of one or more of the neuron circuit blocks.

8. The method of claim 7 wherein the plurality of neuron circuit blocks are further comprised of axons to output signals and dendrites to receive signals, and the method further comprises:

positioning the axons and dendrites at common locations across each of the neuron circuit blocks.

9. The method of claim 8 further comprising:

orienting the plurality of neuron circuit blocks at an angle relative to the plurality of synapse blocks.

10. The method of claim 7 further comprising:

embedding at least one of the synapse blocks within at least one of the neuron circuit blocks.

11. A design structure tangibly embodied in a machine-readable medium for designing, manufacturing, or testing an integrated circuit, the design structure comprising:

a plurality of synapse blocks electrically connected to a plurality of neuron circuit blocks, the plurality of synapse blocks comprising a plurality of neuromorphic circuits, each neuromorphic circuit comprising;

a field effect transistor in a diode configuration electrically connected to variable resistance material, the variable resistance material providing a programmable resistance value;

a first junction electrically connected to the variable resistance material and an output of one or more of the neuron circuit blocks; and

a second junction electrically connected to the field effect transistor and an input of one or more of the neuron circuit blocks.

12. The design structure of claim 11, wherein the design structure comprises a netlist.

13. The design structure of claim 11, wherein the design structure resides on storage medium as a data format used for the exchange of layout data of integrated circuits.