Interfacing PDM MEMS microphones with PFM spiking systems: Application for Neuromorphic Auditory Sensors

Fuente: arXiv
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Main Authors: Jimenez-Fernandez, Angel, Gutierrez-Galan, Daniel, Rios-Navarro, Antonio, Dominguez-Morales, Juan Pedro, Jimenez-Moreno, Gabriel
Format: Preprint
Published: 2019
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author Jimenez-Fernandez, Angel
Gutierrez-Galan, Daniel
Rios-Navarro, Antonio
Dominguez-Morales, Juan Pedro
Jimenez-Moreno, Gabriel
author_facet Jimenez-Fernandez, Angel
Gutierrez-Galan, Daniel
Rios-Navarro, Antonio
Dominguez-Morales, Juan Pedro
Jimenez-Moreno, Gabriel
contents In neuromorphic engineering, computation is commonly performed asynchronously, mimicking the way in which nervous systems process information: spike by spike. The Neuromorphic Auditory Sensor (NAS) has been implemented under this principle: applying different spike-based Signal Processing blocks. Computation in the spike domain requires the conversion of signals from analog or digital representation to the spike domain, which could present a speed constraint in many cases. This paper presents a spike-based system to convert audio information from low-power pulse density modulation (PDM) MicroElectroMechanical Systems (MEMS) microphones into rate coded spike frequencies. These spikes represent the input signal of the NAS, avoiding the analog or digital to spike conversion, and therefore improving the time response of the NAS. This conversion has been done in VHDL as an interface for PDM microphones, converting their pulses into temporal distributed spikes following a pulse frequency modulation (PFM) scheme with an accurate Inter-Spike-Interval, known as "PDM to spikes interface" (PSI). This was tested in two scenarios, first as a stand-alone circuit for its characterization, and then integrated with a NAS for verification. The PSI achieves a Total Harmonic Distortion (THD) of -39.51dB and a Signal-to-Noise Ratio (SNR) of 59.12dB, demands less than 1\% of the resources of a Spartan-6 FPGA and has a power consumption below 5mW.
format Preprint
id arxiv_https___arxiv_org_abs_1905_00390
institution arXiv
publishDate 2019
record_format arxiv
spellingShingle Interfacing PDM MEMS microphones with PFM spiking systems: Application for Neuromorphic Auditory Sensors
Jimenez-Fernandez, Angel
Gutierrez-Galan, Daniel
Rios-Navarro, Antonio
Dominguez-Morales, Juan Pedro
Jimenez-Moreno, Gabriel
Audio and Speech Processing
Sound
Signal Processing
In neuromorphic engineering, computation is commonly performed asynchronously, mimicking the way in which nervous systems process information: spike by spike. The Neuromorphic Auditory Sensor (NAS) has been implemented under this principle: applying different spike-based Signal Processing blocks. Computation in the spike domain requires the conversion of signals from analog or digital representation to the spike domain, which could present a speed constraint in many cases. This paper presents a spike-based system to convert audio information from low-power pulse density modulation (PDM) MicroElectroMechanical Systems (MEMS) microphones into rate coded spike frequencies. These spikes represent the input signal of the NAS, avoiding the analog or digital to spike conversion, and therefore improving the time response of the NAS. This conversion has been done in VHDL as an interface for PDM microphones, converting their pulses into temporal distributed spikes following a pulse frequency modulation (PFM) scheme with an accurate Inter-Spike-Interval, known as "PDM to spikes interface" (PSI). This was tested in two scenarios, first as a stand-alone circuit for its characterization, and then integrated with a NAS for verification. The PSI achieves a Total Harmonic Distortion (THD) of -39.51dB and a Signal-to-Noise Ratio (SNR) of 59.12dB, demands less than 1\% of the resources of a Spartan-6 FPGA and has a power consumption below 5mW.
title Interfacing PDM MEMS microphones with PFM spiking systems: Application for Neuromorphic Auditory Sensors
topic Audio and Speech Processing
Sound
Signal Processing
url https://arxiv.org/abs/1905.00390