A novel and efficient method to initialize FPGA embedded memory content in asymptotically constant time

Abstract

This paper describes analysis and implementation of a new method for maintaining valid content of FPGA memory blocks with an asymptotically constant time synchronous clear ability, that can be useful for (re)initialization to one default value. A particular application can be for high-speed real-time LZ77 [1] lossless compression algorithms, where a dictionary has to be (re)initialized before each run of the implemented compression algorithm. The method is based on two most widely used techniques for clearing the memory content: a linear passage of the memory and clearing each cell by writing a default value and creating a register field providing an (in)valid bit for each memory cell. Our solution combines these two techniques together with the use of FPGA distributed memory blocks implemented in LUTs (Look-Up Tables) to overcome negative features of each previous method without losing the most of positive features. Our solution provides a balance between the two previous techniques and exceeds them in speed, resources utilization and latency of (re)initialization.