Asynchronous-QDI 2D IIR digital filter circuits

This paper investigates the potential of emerging asynchronous quasi delay insensitive (a-QDI) logic devices for the realization of high-speed low-power 2D infinite impulse response digital beam filters. Recently proposed raster-scanned hardware architectures based on direct-form I and wave-digital realization are extended to clock-free asynchronous logic using state-of-the-art asynchronous field programmable gate arrays from Achronix Semiconductor. For the specific class of 2D IIR beam filters based on raster-scanned hardware, it is shown using extensive experimental work that direct-form I architectures greatly benefit from the adoption of a-QDI logic over standard clocked (synchronous) digital circuits while wave-digital filters show no difference in performance. To the author´s knowledge, the proposed 2D IIR hardware circuits are currently the only available realization of 2D IIR filters in the literature based on the new clock-free a-QDI paradigm.