A Design Algorithm for Sequential Circuits Using LUT Rings

This paper shows a design method for a sequential circuit by using a Look-Up Table (LUT) ring. An LUT ring consists of memories, a programmable interconnection network, a feed-back register, an output register, and a control circuit. It sequentially emulates an LUT cascade that represents the state transition functions and the output functions. We present two algorithms for synthesizing a sequential circuit by an LUT ring: The first one partitions the outputs into groups, and realize them by LUT cascades. The second one reduces the evaluation time by using unused memories. We also compare the LUT ring with other methods to realize sequential circuits.