Efficient eye diagram determination of strongly coupled lines for differential signals

A new efficient and accurate eye-diagram determination technique for differential signaling is presented. An efficient eye-diagram for the differential transmission lines is determined by decoupling the coupled lines into effective single lines. Introducing the simplest input bit pattern to determine the worst case inter-symbol interference (ISI), the output response for a single line can be readily determined by using Fast Fourier transform technique (FFT). The proposed technique is compared with SPICE W-model-based simulation that employs pseudorandom bit sequence (PRBS) input signals.