Analog matrix-matrix multiplier for mixed signal matrix multiplications

A computing circuit, comprising:

• an array of crossbars, wherein the array includes a plurality of signal rows and a plurality of signal columns;
• a plurality of resistive processing units (RPUs) positioned at intersections of the plurality of signal rows and the plurality of signal columns;
• and
• a controller module coupled to an input side and to a read-out side of the plurality of signal rows and the plurality of signal columns, wherein the controller module is configured to:
• initialize the array without a weight value;
• send a first set of pulse signals representing a first input matrix through the plurality of signal rows;
• send a second set of pulse signals representing a second input matrix through the plurality of signal columns;
• detect one or more coincidences of pulse signals at the intersections of the plurality of signal rows and the plurality of signal columns;
• measure a resultant signal value at e each of the one or more coincidences of pulse signals;
• and
• update a resultant matrix output of the array using the measured resultant signal value at the detected coincidences of pulse signals.

A method of performing a matrix to matrix multiply operation on a computing chip, comprises:

• operating a first plurality of signal generators to generate a first set of pulse signals stochastically;
• sending the first set of pulse signals through a plurality of signal rows in an array of cross-bar elements;
• operating a second plurality of signal generators to generate a second set of pulse signals stochastically;
• sending the second set of pulse signals through a plurality of signal columns in an array of cross-bar elements;
• detecting one or more coincidences of pulse signals at intersections of the plurality of signal rows and the plurality of signal columns;
• measuring a resultant voltage or resistance at each of the one or more coincidences of pulse signals;
• and
• updating a resultant matrix output of the array using the measured resultant voltage or resistance at each of the one or more coincidences of pulse signals.