March 19, 2009 -- In an SOC physical design flow, it is very important that there is correlation with respect to timing between various tools. Perfect timing correlation between tools leads to faster timing closure, and thus, reduction in cycle time. For instance, the synthesis tool and the place-and-route tool, the timing-signoff tool and the implementation tool all should produce timing data consistent with each other.
But even unexpected differences can creep in. There could be changes, for example, in the version of timing-signoff tool between the start of a project and the final signoff. If the tool changes, it is necessary to ensure that there is perfect timing correlation between the two versions of the signoff tool before the new version of tool is adopted. Again, there is always a need to establish timing correlation between different stages of physical design flow. For example, timing correlation between pre-clock-tree and post-clock-tree databases, or pre-routed and post-routed databases, are both necessary. The timing correlation checks can be very exhaustive or can be minimal.
So, there is a need to define and set up a timing-correlation flow, and to automate the whole flow, so that timing correlation can be verified in the minimum possible time, without much manual work.
By Shruti Rakheja and Naveen Sampath Krishna. (Rakheja and Krishna are design engineers at Freescale Semiconductor, Inc.)
This brief introduction has been excerpted from the original copyrighted article.
View the entire article on the EDN Magazine website.
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