Sensor-processing systems including neuromorphic integrated circuits and methods thereof

A method of conditional neural network operation in a sensor-processing system upon detection of a credible keyword, comprising:

• operating a pulse-density modulation (“PDM”) microphone, a PDM decimation module, a time domain-processing module, and a frequency domain-processing module,
• wherein operating the time domain-processing module and the frequency domain-processing module includes identifying one or more signals of an audio sample in a time domain or a frequency domain if the one or more signals are present;
• powering on and operating a lower-powered secondary neural network if the one or more signals are present to determine if the one or more signals includes a keyword;
• and
• powering on and operating a larger, higher-powered primary neural network if the one or more signals include a keyword, wherein the primary neural network confirms the one or more signals includes a keyword.

A method of microphone-mode switching for a sensor-processing system, comprising:

• operating a pulse-density modulation (“PDM”) microphone in a lower-frequency mode to conserve power;
• operating a time domain-processing module and a frequency domain-processing module, the operations including:
• extracting features from an audio sample;
• and
• determining if one or more signals are present in a time domain or a frequency domain;
• operating the PDM microphone in a higher-frequency mode for better signal-to-noise ratio if the one or more signals are present;
• and
• operating a PDM decimation module in accordance with either the lower-frequency mode or the higher-frequency mode to format the audio sample for use in a sensor-processing system.

A method for a sample holding tank of a sensor-processing system, comprising:

• operating a pulse-density modulation (“PDM”) microphone and a PDM decimation module to format an audio sample for use in the sensor-processing system;
• sending the audio sample to both the holding tank and one or more sample-processing modules;
• operating a time domain-processing module and a frequency domain-processing module to extract features from the audio sample;
• operating a neural network to determine if the features extracted from the audio sample include one or more keywords;
• and
• pulling the audio sample from the sample holding tank and sending the audio sample to the one or more sample-processing modules for additional but different sample processing to confirm the features extracted from the audio sample include the one or more keywords.