# US 11,442,695 B2 · Product-sum operation device, neuromorphic device, and method for determining malfunction in product-sum operation device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,695 B2 - Document ID: US11442695B2 - Status: Granted - Kind: B2 - Application number: 16/766,426 - Filed: 2018-12-12 - Published: 2021-02-04 - Granted: 2022-09-13 - Earliest claimed: 2017-12-28 - Assignees: TDK Corporation - Applicants: TDK Corporation - Inventors: Tatsuo Shibata - Web page: https://patentgrep.com/patent/US11442695B2 ## CPC - G06F 7/5443: {Sum of products (for applications thereof, see the relevant places, e.g. G06F17/10, H03H17/00)} - G01R 31/50: Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections (testing of sparking plugs H01T13/58) - G06N 3/04: Architecture, e.g. interconnection topology - G06N 3/048: Activation functions - G06N 3/0499: Feedforward networks - G06N 3/065: Analogue means - G11C 7/1006: {Data managing, e.g. manipulating data before writing or reading out, data bus switches or control circuits therefor} - G11C 11/161: {details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell} - G11C 11/1655: {Bit-line or column circuits} - G11C 11/18: using Hall-effect devices - G11C 11/54: using elements simulating biological cells, e.g. neuron - G11C 13/0021: {Auxiliary circuits} - G11C 13/0026: {Bit-line or column circuits} - G11C 29/50008: {of impedance} - H10B 61/00: Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices - H10B 63/80: {Arrangements comprising multiple bistable or multi-stable switching components of the same type on a plane parallel to the substrate, e.g. cross-point arrays} - H10N 50/10: Magnetoresistive devices - H10N 50/80: Constructional details - H10N 50/85: Materials of the active region - H10N 59/00: Integrated devices, or assemblies of multiple devices, comprising at least one galvanomagnetic or Hall-effect element covered by groups H10N50/00 - H10N52/00 (MRAM devices H10B61/00) - H10N 70/231: {based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect} - G01R 31/52: Testing for short-circuits, leakage current or ground faults - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G06N: COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS - G11C: STATIC STORES (semiconductor memory devices H10B) - H10B: ELECTRONIC MEMORY DEVICES - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract A product-sum operation device includes a product operator, a sum operator, and a malfunction determiner. The product operator includes a plurality of product operation elements (10AA) to (10AC), and each of the plurality of product operation elements (10AA) to (10AC) is a resistance change element. The sum operator includes an output detector that detects the sum of outputs from the plurality of product operation elements (10AA) to (10AC). The malfunction determiner determines that a malfunction has occurred when the sum detected by the output detector exceeds a specified value. The specified value is a value equal to or greater than a maximum value of the sum that can be detected by the output detector when the plurality of product operation elements (10AA) to (10AC) all operate normally. ## Claims ### Claim 1 A product-sum operation device comprising a product operator, a sum operator, and a malfunction determiner, wherein the product operator includes a plurality of product operation elements connected to same line connected to the sum operator, each of the plurality of product operation elements is a resistance change element, the sum operator includes an output detector configured to detect a sum of outputs from the plurality of product operation elements, the malfunction determiner is configured to determine that a malfunction has occurred in at least one of the plurality of product operation elements when the sum detected by the output detector exceeds a specified value, and the specified value is a value equal to or greater than a maximum value of the sum that can be detected by the output detector when the plurality of product operation elements all operate normally. ### Claim 2 (depends on 1) The product-sum operation device according to claim 1, wherein the resistance change element has a write terminal, a common terminal, and a read terminal. ### Claim 3 (depends on 1) The product-sum operation device according to claim 1, wherein the resistance change element is a magnetoresistive effect element exhibiting a magnetoresistive effect, and the magnetoresistive effect element includes: a magnetization free layer having a domain wall; a magnetization fixed layer whose magnetization direction is fixed; and a nonmagnetic layer sandwiched between the magnetization free layer and the magnetization fixed layer. ### Claim 4 (depends on 1) The product-sum operation device according to claim 1, wherein the product operator includes at least a first column having the plurality of product operation elements and a second column having a plurality of product operation elements connected to the same line different from the first column, the sum operator includes at least a first output detector configured to detect a sum of outputs from the plurality of product operation elements in the first column and a second output detector configured to detect a sum of outputs from the plurality of product operation elements in the second column, and the product-sum operation device further comprises a function replacer configured to, when the malfunction determiner has determined that the first column has malfunctioned, cause the plurality of product operation elements in the second column to operate product operations that the plurality of product operation elements in the first column have operated before the malfunction of the first column. ### Claim 5 (depends on 1) The product-sum operation device according to claim 1, further comprising: a malfunction location-identifying unit configured to identify, when the malfunction determiner has determined that some of the plurality of product operation elements have malfunctioned, a malfunctioning product operation element among the plurality of product operation elements; and an input blocker configured to block an input to the malfunctioning product operation element when the malfunction determiner has determined that some of the plurality of product operation elements have malfunctioned, wherein the malfunction location-identifying unit is configured to identify the malfunctioning product operation element by inputting a signal to the plurality of product operation elements through an output side of the plurality of product operation elements. ### Claim 6 (depends on 1) A neuromorphic device comprising the product-sum operation device according to claim 1. ### Claim 7 (depends on 6) The neuromorphic device according to claim 6, further comprising an activation function received to the output of the product-sum operation device, wherein the activation function is set such that an output value from the activation function becomes zero when a value input to the activation function is equal to or greater than a threshold value. ### Claim 8 (depends on 6) The neuromorphic device according to claim 6, wherein a resistance value of each of the plurality of product operation elements during normal operation and a resistance value of each of the plurality of product operation elements during a malfunction differ by three or more orders of magnitude. ### Claim 9 (depends on 6) The neuromorphic device according to claim 6, wherein the output detector is configured to detect an output current value from the plurality of product operation elements. ### Claim 10 (depends on 6) The neuromorphic device according to claim 6, wherein the output detector is configured to detect a charge output from the plurality of product operation elements. ### Claim 11 (depends on 1) A neuromorphic device comprising the product-sum operation device according to claim 1, the product-sum operation device further comprising an output blocker configured to block, when the malfunction determiner has determined that some of the plurality of product operation elements have malfunctioned, outputs from the plurality of product operation elements determined to have malfunctioned. ### Claim 12 (depends on 1) A neuromorphic device comprising the product-sum operation device according to claim 1, wherein the resistance change element is a magnetoresistive effect element exhibiting a magnetoresistive effect, the magnetoresistive effect element includes: a magnetization free layer having a domain wall; a magnetization fixed layer whose magnetization direction is fixed; and a nonmagnetic layer sandwiched between the magnetization free layer and the magnetization fixed layer, and a thickness of the nonmagnetic layer is 2.5 nm or more. ### Claim 13 (depends on 12) The neuromorphic device according to claim 12, wherein the magnetization free layer is a perpendicular magnetization film selected from the group consisting of a Co/Pt multilayer film, a Co/Pd multilayer film, and a CoCrPt alloy film. ### Claim 14 (depends on 1) The product-sum operation device according to claim 1, further comprising: a malfunction location-identifying unit configured to identify, when the malfunction determiner has determined that at least one of the plurality of product operation elements have malfunctioned, a malfunctioning product operation element among the plurality of product operation elements; wherein the malfunction location-identifying unit is configured to identify the malfunctioning product operation element by inputting a signal to the plurality of product operation elements through an output side of the plurality of product operation elements. ### Claim 15 A method for determining a malfunction in a product-sum operation device including a product operator and a sum operator, wherein the product operator includes a plurality of product operation elements connected to same line connected to the sum operator, each of the plurality of product operation elements is a resistance change element, the method comprises: a detection step of detecting a sum of outputs from the plurality of product operation elements, and a determination step of determining that a malfunction has occurred in at least one of the plurality of product operation elements when the sum detected in the detection step exceeds a specified value, and the specified value is a value equal to or greater than a maximum value of the sum that can be detected when the plurality of product operation elements all operate normally.