Dedicated logic cells employing configurable logic and dedicated logic functions

Abstract

A dedicated logic cell in a programmable logic structure is described that comprises the following primary components: a configurable logic function or look-up table (LL), a dedicated logic function (DL), a sequential logic function (LS), and a control logic function (LC). In this illustration, the dedicated logic cell comprises two configurable logic functions, two sequential logic functions, a dedicate logic function, and a control logic function. In some embodiments, the configurable logic function comprises a plurality of look-up tables coupled to a multiplexer with configurable bits that is capable to perform a four 4-input look-up table, one 6-input look-up tables or a 4-to-1 multiplexer. In the first function that operates as the four 4-input look-up table, the dedicated logic cell has four look-up tables for receiving four inputs respectively. In the second function that operates as one 6-input look-up table, a fifth input from a multiplexer and a sixth input from a multiplexer are added to the four inputs. In the third function that operates as a 4-to-1 multiplexer, a multiplexer receives four inputs respectively from the four look-up tables with two select lines.