Modeling, simulation, and measurement considerations of high-speed digital buses

Insight is given into some of the major limiting factors of high-speed buses. It is shown that on loaded backplanes, the propagation delay is a function of the device's trigger threshold. The stub-ringing phenomenon is also discussed. For single, capacitively loaded stubs, the ringing frequency is shown to be lower than what one expects from the widely used quasi-lumped models. A simple dual-stub butterfly model is introduced to predict the ringing of backplanes. This model predicts the stub ringing in high-impedance states of TTL buses or high-level states of BTL (backplane transceiver logic) buses.>