Design And Implementation Of Signal Integrity Automated Simulation Tool Based On DDR5

With the continuous development of chip technology,the tiny gate channel length makes the switching speed of transistors further accelerated,and the signal integrity problem in DDR5 products becomes more and more obvious as the data rate increases.Statistical eye diagram methods allow for a quick assessment of signal integrity issues.However,the statistical algorithms in the current EDA tools are based on the linear time-invariant assumption,and do not fully consider the crosstalk,jitter,noise and other issues in the link and the nonlinear characteristics of active devices.In addition,in terms of link design,when the physical and electrical characteristics of DDR5 link components change,there is a lack of a scientific method for designers to understand the impact of link components on link performance.Designers often rely on experience to optimize the design and cannot quantitatively analyze.Therefore,it has become an urgent problem to comprehensively evaluate the performance of DDR5 links and use scientific methods to provide a complete set of signal integrity solutions.Aiming at the problem of statistical eye diagram,this paper proposes a multi-factor doubleedge statistical eye diagram algorithm that can simultaneously consider loss,crosstalk,jitter,voltage noise and edge asymmetry.This algorithm obtains the rising edge of the attack line,the response of the falling edge and the crosstalk data of the victim line through the HSpice simulation tool,and the multi-factor statistical eye diagram can be calculated by specifying the relevant parameters of jitter and noise by the designer.Add forward feedback equalization(FFE),continuous time linear equalization(CTLE),decision feedback equalization(DFE)link equalization technology for lossy links,and support adaptive optimization of equalization parameters.Aiming at the problem of link design optimization,this paper adopts the response surface method(RSM)to construct the mathematical model of the high-speed parallel link.The RSM algorithm is based on the linear decay technique to establish a mathematical statistical model.The physical or electrical characteristics of the link components such as the length of the traces and the traces are used as input,and the eye height and width of the multi-factor statistical eye diagram are used as the system response,and the mathematical model of the DDR5 link is obtained.By specifying the probability density function of the DDR5 link characteristics,the histogram of the system response is obtained by the Monte Carlo method,and the solution set of the input factors that meet the requirements of the eye diagram is given.The DDR5 automatic simulation tool is developed based on Python,and the simple and easy-to-understand GUI interface makes it easier for designers to optimize the design of DDR5 high-speed parallel links.This paper introduces the principle of the multi-factor statistical eye diagram algorithm and design optimization algorithm in detail,as well as the realization of the tool’s structure and functions,and verifies the accuracy and feasibility of the multi-factor statistical eye diagram and design optimization algorithm in the tool.The work of this paper provides a feasible solution for the design of the signal integrity automation simulation tool for high-speed links,and has strong engineering significance.