Pre-emphasis parameter optimization for high speed channels using de-convolution approach

This paper covers a novel technique for quickly determining optimum settings for pre-emphasis parameters used in high speed SerDes links. Time domain de-convolution is used for determining the optimum pre-emphasis settings for the high speed differential channel. The optimization is done in the frequency domain through FFT and method of exhaustion. The results from the analysis are applied on 10Gbps SerDes links of a top-of-rack Ethernet switch. Measurement results from a vector network analyzer and oscilloscope are shown as part of the verification. This paper is especially useful for optimizing the SerDes channels and it helps the engineers tune the transmitter pre-emphasis without heavily depending on AMI models, and can be treated as a complementary method to the conventional simulation techniques using IBIS models. The proposed method can be applied at the early and troubleshooting stage of the high speed link design.