Fast coupled noise estimation for crosstalk avoidance in the MCG multichip module autorouter

A multilayer, multichip module (MCM) router, called MCG, is introduced for x-y routing. An efficient method has been derived to allow candidate routes for the nets to be considered simultaneously for compatibility rather than incrementally extending routes or routing one net at a time as in many other techniques. This allows incorporation of accurate models for determining the potential for crosstalk problems during the routing process. MCG incorporates a crosstalk avoidance procedure which facilitates correct-by-design routing in systems susceptible to noise problems. In comparisons with other routers on industrial benchmarks, the MCG router has shown substantial improvement in routing density, number of layers, number of vias, and total interconnect length over routers such as V4R and SLICE. Our test results show up to 18% improvement in via count and up to 33% improvement in the required number of routing layers for these examples over V4R. One of the benchmarks presented contains 37 VHSIC gate arrays, over 7000 nets, and over 14000 pins (pads). Routing at finer pitches with crosstalk avoidance shows a further improvement in interconnect density.