Storage device and neural network apparatus

A storage device comprising:

• a plurality of storage circuits, each including a shift register and storing weights being continuous values;
• an initialization circuit;
• an update control circuit;
• and
• a readout control circuit, wherein
• the shift register includes a plurality of cells, each being arranged in series and storing information, the shift register being capable of shifting a position of the cell storing the information among the plurality of cells in a forward direction and a reverse direction in units of cells, a position of each of the plurality of cells corresponding to the weight, the weight corresponding to each of the plurality of cells continuously increasing or decreasing together with a change in the position in the forward direction,
• the initialization circuit is configured to, for each of the plurality of storage circuits, write the information to one of the plurality of cells included in the shift register,
• the update control circuit is configured to, for each of the plurality of storage circuits,
• receive an update amount of the weight, and
• shift a position of the cell storing the information in a direction corresponding to a sign of the update amount by a number of cells corresponding to an absolute value of the update amount, and
• the readout control circuit is configured to, for each of the plurality of storage circuits,
• read out the information stored in the plurality of cells, and
• output an output value according to the weight corresponding to the position of the cell storing the information.

A neural network apparatus comprising:

• an arithmetic circuit configured to execute arithmetic processing according to a neural network;
• an inference weight storage circuit configured to store a plurality of inference weights used in the arithmetic processing according to the neural network executed by the arithmetic circuit;
• a learning weight storage circuit configured to, in a learning process of the neural network, store a plurality of weights being continuous values corresponding to the plurality of inference weights;
• and
• a learning control circuit configured to
• control, in the learning process, the learning weight storage circuit to update each of the plurality of weights based on an operation result of the arithmetic circuit, and,
• control, after the learning process, the inference weight storage circuit to store, as the plurality of inference weights, the plurality of output values corresponding to the plurality of weights stored in the learning weight storage circuit,
• wherein the learning weight storage circuit includes:
• a plurality of storage circuits, each including a shift register and storing weights being continuous values;
• an initialization circuit;
• an update control circuit;
• and
• a readout control circuit, wherein
• the shift register includes a plurality of cells, each being arranged in series and storing information, the shift register being capable of shifting a position of the cell storing the information among the plurality of cells in a forward direction and a reverse direction in units of cells, a position of each of the plurality of cells corresponding to the weight, the weight corresponding to each of the plurality of cells continuously increasing or decreasing together with a change in the position in the forward direction,
• the initialization circuit is configured to, for each of the plurality of storage circuits, write the information to one of the plurality of cells included in the shift register,
• the update control circuit is configured to, for each of the plurality of storage circuits,
• receive an update amount of the weight, and
• shift a position of the cell storing the information in a direction corresponding to a sign of the update amount by a number of cells corresponding to an absolute value of the update amount, and
• the readout control circuit is configured to, for each of the plurality of storage circuits,
• read out the information stored in the plurality of cells, and
• output an output value according to the weight corresponding to the position of the cell storing the information.