FLEXIBLE CARRY SCHEME FOR FIELD PROGRAMMABLE GATE ARRAYS

A fast, flexible carry scheme for use in clustered field programmable gate array architectures is described. Each cluster has a cluster carry input node, a cluster carry output node, a cluster carry output circuit having an output coupled to the cluster carry output node, a first input coupled to the cluster carry input node, and a second input and a plurality of logic modules each comprising a logic function generator circuit coupled to a carry circuit. The logic modules are coupled in a series carry arrangement between the cluster carry input node and the second input of the cluster carry output circuit such that the least significant bit of an arithmetic logic circuit can be programmably placed in any of the logic modules.