High speed product term assignment for output enable, clock, inversion and set/reset in a programmable logic device

摘要

A macrocell for a programmable logic device includes private product term assignments to provide various functions including set and reset, output enable, clocking, and inversion. Each of these additional functions is provided by assigning one of the product terms associated with the macrocell to perform one of these functions locally. By means of additional logic circuitry these functions are achieved either singly or in combination for a particular macrocell, thus improving macrocell flexibility and in some cases conserving pins of the chip of which the programmable logic array is a part.