All-Region Statistical Model for Delay Variation Based on Log-Skew-Normal Distribution

作者：Balef Hadi Ahmadi^*; Kamal Mehdi; Afzali Kusha Ali; Pedram Massoud

来源：IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 2016, 35(9): 1503-1508.

DOI：10.1109/TCAD.2015.2511148

• Delay modeling
• process variation
• statistical modeling

In this paper, we propose a single probability density function for the distributions of the delay in the presence of the process variation for different regions of operation. The delay variation model is inspired by considering the analytical current models for each operating region. Based on these models, we suggest using the log-skew-normal distribution for modeling the delay variation for a wide range of supply voltages from the subthreshold to above-threshold regions. To assess the accuracy of the proposed delay distribution, the mean, standard deviation, skewness, 99th percentile, and yield of the proposed distribution are compared with those of the normal and log-normal distributions using the Monte Carlo (MC) simulations for different circuits in both bulk and FinFET technologies. The results show a higher accuracy for the proposed distribution in all regions of operation. Also, the proposed model enables us to obtain the 3 sigma yield of the distribution using up to 3.4 times less MC simulation time.

• 出版日期2016-9