Non-volatile memory accelerator for artificial neural networks

A method for performing multiply-and-accumulate (MAC) operations for an artificial neural network (ANN) accelerator, comprising:

• receiving digital input data at a non-volatile memory (NVM) crossbar module including a plurality of digital-to-analog converters (DACs), an NVM crossbar and a plurality of analog-to-digital converters (ADCs);
• converting, by the DACs, the digital input data into a plurality of analog voltage signals;
• converting, by the NVM crossbar, the analog voltage signals into a plurality of MAC signals using a plurality of MAC cells, each MAC cell including one or more NVM elements programmed to a conductance level representing one of a plurality of unipolar weights of an ANN;
• converting, by the NVM crossbar, the analog voltage signals into a correction signal using a plurality of correction cells, each correction cell including one or more NVM elements programmed to a predetermined conductance level;
• and
• correcting each MAC signal based on the correction signal.

A non-volatile memory (NVM) crossbar, comprising:

• a plurality of row signal lines configured to receive input analog voltage signals;
• a plurality of multiply-and-accumulate (MAC) column signal lines;
• a correction column signal line;
• a MAC cell disposed at each intersection of a row signal line and a MAC column signal line;
• and
• a correction cell disposed at each intersection of a row signal line and the correction column signal line,
• where each MAC cell includes one or more NVM elements programmed to a conductance level representing one of a plurality of unipolar weights of an ANN, and each correction cell includes one or more NVM elements programmed to a predetermined conductance level,
• where each MAC column signal line is configured to generate a MAC signal based on the input analog voltage signals and the respective MAC cells, and the correction column signal line is configured to generate a correction signal based on the input analog voltage signals and the correction cells, and
• where each MAC signal is corrected based on the correction signal.