Layout of a Neuromorphic Integrated Circuit for Differential Motion Detection

The circuitry to compute differential motion is found in the biological retina of many animals. If there is a difference between the motion (speed) in the central and peripheral visual receptive field, the ganglion cell in the retina will generate a spike which is relayed via the axon to the brain. In this paper, we have designed layout for biological cells namely - the photoreceptor cell and the bipolar cell, which are further combined together to develop a layout of a circuit for computation of differential motion. The layout has an analog adder which is used to sum the output responses of the bipolar cell. We have also simulated the schematic of individual cells and the entire system to verify the results and performed a layout versus schematic check (LVS). The layout simulation results of individual cells and the system are compared with the results from the schematic and biological experiments which are available in the published literature.