Performance analysis and model-to-hardware correlation of multigigahertz parallel bus with transmit pre-emphasis equalization

The performance of multigigahertz systems is adversely impacted by nonideal physical effects such as attenuation, crosstalk, impedance mismatches, intersymbol interference, and component and parameter variations. Many of these nonideal physical effects can be mitigated by selecting proper signaling topologies and techniques, by using judicious design rules, and by applying advanced circuitry and signal processing techniques. However, the component and parameter variations due to process and environmental conditions are more difficult to overcome, and their impact on a multigigahertz system needs to be quantified in order to ensure robust system operation under worst case operating conditions. This paper investigates the sensitivity of the performance of multigigahertz systems to component and parameter variations using simulations. The modeling accuracy of the equalized channel is correlated with a prototype system operating at data rates of up to 8 Gb/s. The sensitivity of equalization taps to variations in channel parameters is also studied. Finally, a measurement-based simulation method of evaluating the impact of transmitter and receiver jitter on the system timing margin is presented.