Load Reduction and Adaptive Pull-Up Strategies for Time Delay Reduction in High-Resolution AER Sensors

The Address Event Representation (AER) protocol is widely used in pixelated neuromorphic systems to implement word-serial asynchronous transmission links. The data is encoded in time or frequency and transferred from the pixel to the receiver in the form of events through a shared channel. Asynchronous sensors benefit from lower data throughput, power consumption, and latency; however, they present several timing limitations to scale the size of the array, since delay in the transmission line and collisions in the readout channel corrupt the timing information. This paper analyzes the effect of increasing the number of pixels in terms of transmission delay and proposes several design guidelines to overcome scaling limitations in high-resolution pixel arrays. The results of the post-layout simulation verify the effectiveness of the design proposals, achieving a reduction of more than 70% in the time delay of the request line.