Median filter that re-uses comparators when sorting data

Abstract

Techniques are provided for sorting input data values using a sorting circuit. The sorting circuit includes a single stage of comparators coupled to a bank of registers. Multiplexors and a sequencer are used to route the comparator outputs back to the comparator inputs such that the comparators may be re-used over multiple sorting phases so as to order an input sequence of data values into a partially-sorted sequence or into a completely-sorted sequence that is monotonically increasing or decreasing. By re-using the comparators, the hardware required for such sorting is significantly reduced relative to conventional techniques. Also described are techniques for median filtering, which use a sorted sequence as output by the sorting circuit described herein.