Fast buffering for optimizing worst slack and resource consumption in repeater trees
Christoph Bartoschek, Stephan Held, Dieter Rautenbach, Jens Vygen · 2009
We present a very fast algorithm for buffering repeater trees. We scan a given preliminary topology in a bottom-up fashion and insert buffers and inverters, respecting the parities of the sinks. Information obtained by preprocessing allows for very fast decisions. To bound the number of shielding repeaters, they are only used where necessary to maximize the worst slack. Furthermore, instead of using a fixed set of repeater positions, they are computed on the fly based on the already buffered subtrees. Another key feature of our algorithm is that we modify the preliminary topology while buffering in order to avoid parallel wires or too many inverters.