Investigation of Critical Path Selection for In-Situ Monitors Insertion

摘要

The performance and low power requirement are becoming more and more challenging to fulfill for consumer product. On the opposite, a low failure rate at SoC level must be guaranteed to the end-customer. In that context, the insertion of in-situ slack monitor is known to be promising and efficient solution to manage the wear-out and more generally to minimize all margins related to manufacturing variations and operating conditions. As far as in-situ slack monitors are located in functional path, the choice of endpoint register and the number of monitors are of prime importance. This paper deals with a methodology of path selection in a context of monitor insertion in digital block without pattern availability. Basically, the timing of data path arriving to an endpoint register is analyzed, and a weight is calculated as a figure of merit. This work accounts for stochastic dispersion, aging, global corner process, voltage and temperature variations. The important role played by the sub-critical path is illustrated with silicon measurement.