一种改进型FBT时钟树结构

针对混合型鱼骨平衡树(FBT)时钟结构的优缺点,结合宏单元的特性,提出了一种针对触发器与宏单元共存的改进型FBT时钟树结构,并总结出一种快速实现该时钟树的方法。在相同条件下,采用该方法实现的时钟树结构与二叉树型、鱼骨型时钟结构和传统的FBT时钟树结构进行比较,结果显示:鱼骨型时钟结构的时序质量最差；改进型FBT时钟树比二叉树型时钟树减少了15%的时钟延时和35%的时钟偏差,且整个过程的实现时间是传统FBT时钟树的30%。

An Improved Fishbone Balance Tree

Based on the advantages and disadvantages of FBT(fishbone balance tree), and combined with the properties of macrocells, an improved FBT was proposed for the coexistence of flip-flops and macrocells. An approach for rapidly implementing this clock tree was presented. Under the same conditions, the proposed clock tree was compared with the binary trees, the fishbone clock trees and the traditional FBTs. The results showed that the fishbone clock tree had the worst timing quality, and the proposed FBT had a 15 percent of reduction in clock latency and 35 percent of reduction in clock skew compared with the binary tree. Furthermore, the implementation time of the whole process took only 30 percent of the traditional FBT.