US 2021/0264241 A1 · OPTICAL MULTIPLY AND ACCUMULATE UNIT

Abstract

Processing elements for neural network accelerators, and methods of operating the processing elements. Each of a plurality of synapse lanes outputs an electrical signal indicative of a value of a synapse. Each electrical signal is received by a respective optical AND unit including an optical microring resonator that selectively couples an optical signal indicative of the value of an input neuron based at least in part on the received electrical signal. The output of each optical AND unit is provided to either an electrical multiply and accumulate unit, or a respective interferometer of a plurality of interferometers. The interferometers are arranged in series so that optical signals are sequentially summed and shifted by each interferometer. The last interferometer outputs a shifted and accumulated sum of the outputs received from the optical AND units. In either case, the accumulated sum may then be used to generate an output neuron.

Claims20

Dependent claims

A processing element for a neural network accelerator, comprising:

a first synapse lane configured to output a first electrical signal indicative of a value of a first synapse during a first cycle of an output neuron calculation;
and
a first optical AND unit including:
a first electrical input operatively coupled to the first synapse lane,
a first optical input configured to receive a first optical signal indicative of the value of a first input neuron transmitted during the first cycle of the output neuron calculation,
a first optical output, and
a first optical microring resonator configured to selectively couple the first optical signal from the first optical input to the first optical output based at least in part on a characteristic of the first electrical signal.

4 more elements

A method of operating a processing element for a neural network accelerator, comprising:

outputting a first electrical signal from a first synapse lane, the first electrical signal indicative of a value of a first synapse during a first cycle of an output neuron calculation;
receiving the first electrical signal at a first electrical input of a first optical AND unit;
receiving a first optical signal at a first optical input of the first optical AND unit, the first optical signal indicative of the value of a first input neuron transmitted during the first cycle of the output neuron calculation;
providing the first electrical signal to a first optical microring resonator;
and
selectively coupling the first optical signal from the first optical input to a first optical output of the first optical AND unit with the first optical microring resonator based at least in part on a characteristic of the first electrical signal.

3 more elements

Dependencies are inferred from the claim text.

Optical multiply and accumulate unit

Life of this patent

Optical multiply and accumulate unit

Life of this patent

Abstract

Claims20