Can the lightweight timing model take into account the voltage factor?

[wenchen]

Hi Chris,

I read your paper "An Open-source Lightweight Timing Model for RapidWright" and I find it very useful for my research topic. 

In this paper, you propose a equation based delay model:

delay(TG) = k0 + k1⋅L(TG) + k2⋅d(TG). 

Is it possible to add the voltage factor into the model?

If so, which parts of this formula will be affected by voltage? Noting that the desired voltage range is about 0.6v-0.85v, far exceeding the threshold voltage.

Thank you!

Wen Chen

[Pongstorn Maidee]

Wen Chen,

Without knowing any specific of what you are trying to do, I will comment in general.

Concept:

The equation is used to capture the delay of various routing resources with reasonable accuracy. The current model capture delays versus types of resources and which large tiles they cross. Considering more variables, such as voltage and temperature, will make the delay surface of the data set more complex. As a result, more linear terms (or higher order terms) would be needed to model the data set. Alternatively, if the delay can still be fitted to the equation for a given voltage and temperature, a matrix of equations should also work. 

Implementation:

How to extract the delay considering voltage and temperature?  Delay extraction is the most difficult steps. 

How to use the model?  Once you got the data and the model, the answer to this will determine how useful is the model.  The easiest is to apply uniform voltage and temperature through the whole device. But, it may not be useful in practice. 

Best,

Pongstorn