# US 2021/0240944 A1 · Multiply-accumulate device and multiply-accumulate method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0240944 A1 - Document ID: US20210240944A1 - Status: Published application - Kind: A1 - Application number: 16/973,237 - Filed: 2019-07-05 - Published: 2021-08-05 - Earliest claimed: 2018-07-12 - Assignees: Sony Corporation - Applicants: Sony Corporation - Inventors: Yasushi Fujinami; Hiroyuki Yamagishi - Web page: https://patentgrep.com/patent/US20210240944A1 ## CPC - G06G 7/60: for living beings, e.g. their nervous systems {; for problems in the medical field} - G06F 7/5443: {Sum of products (for applications thereof, see the relevant places, e.g. G06F17/10, H03H17/00)} - G06G 7/16: for multiplication or division {(G06G7/19 and G06G7/24 take precedence; measuring electric power G01R21/00)} - G06G 7/184: using capacitive elements - G06N 3/045: Combinations of networks - G06N 3/0464: Convolutional networks [CNN, ConvNet] - G06N 3/049: Temporal neural networks, e.g. delay elements, oscillating neurons or pulsed inputs - G06N 3/065: Analogue means - G06G: ANALOGUE COMPUTERS (analogue optical computing devices G06E3/00) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G06N: COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS ## Abstract A multiply-accumulate device (10) includes: a comparison unit (18) that compares, with a threshold voltage, a voltage generated by an electric charge stored in a storage unit (14), and outputs an output signal at timing at which the voltage exceeds the threshold voltage; and a control circuit (110) that reduces, based on a predetermined set value, a charging current to the storage unit (14) from a plurality of input units (13) connected to the storage unit (14). ## Claims ### Claim 1 A multiply-accumulate device comprising: a comparison unit that compares, with a threshold voltage, a voltage generated by an electric charge stored in a storage unit, and outputs an output signal at timing at which the voltage exceeds the threshold voltage; and a control circuit that reduces, based on a predetermined set value, a charging current to the storage unit from a plurality of input units connected to the storage unit. ### Claim 2 (depends on 1) The multiply-accumulate device according to claim 1, wherein the control circuit lowers the charging current by changing a number of the plurality of input units which output signals to the storage unit. ### Claim 3 (depends on 2) The multiply-accumulate device according to claim 2, wherein the control circuit changes the number of the plurality of input units when a first time is reached. ### Claim 4 (depends on 2) The multiply-accumulate device according to claim 2, wherein the control circuit lowers the charging current by controlling switch units provided in the plurality of input units. ### Claim 5 (depends on 2) The multiply-accumulate device according to claim 2, wherein the control circuit lowers the charging current by stopping an output of a multiplier-accumulator in a previous stage or an output buffer connected to the multiplier-accumulator in the previous stage. ### Claim 6 (depends on 1) The multiply-accumulate device according to claim 1, wherein the control circuit lowers the threshold voltage supplied to the comparison unit. ### Claim 7 (depends on 6) The multiply-accumulate device according to claim 6, wherein the control circuit lowers the threshold voltage based on a value of the voltage of the storage unit. ### Claim 8 (depends on 7) The multiply-accumulate device according to claim 7, wherein the control circuit lowers the threshold voltage so that the threshold voltage becomes equal to or higher than a maximum value of a voltage of the storage unit at a first time when the output signal is output from the comparison unit at earliest timing. ### Claim 9 (depends on 8) The multiply-accumulate device according to claim 8, wherein the control circuit lowers the threshold voltage from the first time so that the threshold voltage becomes equal to or lower than a minimum value of a voltage of the storage unit at a second time having a same time length as a time length of the first time. ### Claim 10 (depends on 1) The multiply-accumulate device according to claim 1, further comprising: a first clip circuit that clips a minimum value of the output signal to a first value; and a second clip circuit that clips a maximum value of the output signal to a second value. ### Claim 11 (depends on 10) The multiply-accumulate device according to claim 10, wherein the first clip circuit is composed of an AND circuit. ### Claim 12 (depends on 10) The multiply-accumulate device according to claim 10, wherein the second clip circuit is composed of an OR circuit. ### Claim 13 (depends on 1) The multiply-accumulate device according to claim 1, further comprising a calculation device that calculates the set value. ### Claim 14 A multiply-accumulate method comprising: comparing, with a threshold voltage, a voltage generated by an electric charge stored in a storage unit, and outputting an output signal at timing at which the voltage exceeds the threshold voltage; and reducing, based on a predetermined set value, a charging current to the storage unit from a plurality of input units connected to the storage unit.