Quantitative Characterization of Neuromorphic Neural Circuits

NeuroDyn is a neuromorphic very large scale integrated circuit (VLSI) capable of modelling four interconnected Hodgkin-Huxley like neurons coupled through twelve chemical synapses. The 384 digitally programmable parameter space specifies ion conductances, reversal potentials and ion channel gating variables. Errors during the manufacturing process can result in a large mismatch between a specified design parameter and the value realized in the hardware. Statistical data assimilation (SDA) is a technique that can estimate parameters in a non-linear dynamical system. By inputting a current designed to probe the full dynamical range of the chip and then measuring the four state variables of the NaKL Neuron (V, m, h, n) we can estimate the mismatch between the programmed and physical parameters. Characterization of the errors in the VLSI chip will help standardize and render useful all manufactured neuromorphic chips such that they can interchangeably be used for applications and research.