Via-configurable high-performance logic block involving transistor chains

A via-configurable logic block architecture for a Structured ASIC has a plurality of MOSFET transistor chains connected to one another through vias. In one embodiment there are three chains and the first transistor chain is a NFET transistor chain, the second transistor chain is a PFET transistor chain, and the third transistor chain is a NFET transistor chain. The first, second and third transistor chains are formed into devices made of transistors that are selected from a voltage threshold group consisting of LVT, SVT and HVT devices, where the first and third transistor chains are formed into devices from a voltage threshold group that is different from one another. In another embodiment transistor drive strength may be varied in the transistor chains of the logic block. In yet another embodiment both voltage threshold and drive strength may be varied together in a symmetrical manner.