Skew-aware polarity assignment in clock tree

Autor: Po-Yuan Chen, TingTing Hwang, Kuan-Hsien Ho
Rok vydání: 2009
Předmět:
Zdroj: ACM Transactions on Design Automation of Electronic Systems. 14:1-17
ISSN: 1557-7309
1084-4309
DOI: 10.1145/1497561.1497574
Popis: In modern sequential VLSI designs, clock tree plays an important role in synchronizing different components in a chip. To reduce peak current and power/ground noises caused by clock network, assigning different signal polarities to clock buffers is proposed in previous work. Although peak current and power/ground noises are minimized by signal polarities assignment, an assignment without timing information may increase the clock skew significantly. As a result, a timing-aware signal polarities assigning technique is necessary. In this article, we propose a novel signal polarities assigning technique which can not only reduce peak current and power/ground noises simultaneously but also render the clock skew in control. The experimental result shows that the clock skew produced by our algorithm is 94% of original clock skew in average while the clock skews produced by three algorithms (Partition, MST, Matching) in the absence of post clock tuning steps in the previous work are 235%, 272%, and 283%, respectively. Moreover, our algorithm is as efficient as the three algorithms of the previous work in reducing peak current and power/ground noises.
Databáze: OpenAIRE