Thank you Charles; On Sat, 2007-10-13 at 23:56 -0400, Charles MacDonald wrote: > At the edges, i suspact that it all boils down to applying the math to > the real world. the variables are such that there is probaly still some > cut-and-try involved. > Randy McLeod helped me find an article that gives the depth of answer I wanted. You might like to read it at: http://en.wikipedia.org/wiki/Clock_distribution_network Reference: E. G. Friedman, Clock Distribution Networks in Synchronous Digital Integrated Circuits , Proceedings of the IEEE, Vol. 89, No. 5, pp. 665-692, May 2001. -- Regards Bill