Abstract: A signal distribution tree is constructed from the leaves to the root by pairing sinks having similar locations, latency requirements and generating function requirements, then determining the minimum cost route or routes between paired sinks, establishing at least one drive point for each minimum cost path which drive point will satisfy the latency requirements for the pair of sinks it serves and then treating each resulting set of drive points as a new sink to be paired while removing the initial sinks from the list of sinks to be paired, continuing this process iteratively until a single set of drive points results and, finally, connecting the signal source to one of the drive points in the final set.

Abstract: A method and apparatus for designing very large scale integrated circuit devices, most particularly level sensitive scan design (LSSD) devices, by inclusion of a plurality of distributed delay lines originating at input terminals of the device, and controlling the inhibiting and enabling of driver circuits connected to the output terminals of the device, as required to regulate operation of device drivers during a plurality of testing operations.