Fishbone And Cts Clock Tree Compared

With the progress of technology, the physical design become more and more complicated. For the concern of this, the design always separates the clock and function as two different parts. The clock tree is an essential technique for SoC design, which requires more improvements.This paper focus on the clock tree in high performance ASIC circuit, includes fishbone clock structure and clock tree synthesis in Astro. And compare the clock skew and differences between them.First of all, we disquisition and analyse the actuality of the clock structure study of ASIC nowadays, and set forth the origin of this paper;Then, after studying concepts of the clock tree, the skew and jitter and their root causes, the clock classification and clock structure, and the timing and timing violations, we mainly introduced the two clock tree design methods which are used most in the recent design, fishbone and clock tree synthesis. Not only the generation of those two clock tree design methods, but also the impact of chip with them.Finally, with a high performance VLSI ASIC design, we did detailed research on the two different clock tree design methods. And we analyze the advantages and disadvantages of fishbone and clock tree synthesis with skew analysis, time and resource.The task we finished in the paper can be sum up as:a: summarize the situation and progress of researches on clock structure of ASIC design.b: Realize the basis cocept of clock tree, clock structure and classification.c: Analyze the two different clock design methods, fishbone and clock tree synthesis.d: Compare the results of fishbone and clock synthesis with a LVSI ASIC design.