Abstract: A method for implementing a programmable critical delay path measurement in-line with the critical path logic cells. Additionally, the delay measurement creates a code to be used with a programmable DLL which indicates the delay of the measured critical path. This code can also be used by an off line First Fail Circuit which can mimic the delay of the critical path and give an indication of the critical path delay. The target of this invention is to create a method to optimize the required operating voltage of an integrated circuit per specific speed requirement, overcoming different process variations, temperatures changes and in die variations.

Abstract: A method and flow for implementing a “clock tree” inside an ASIC using Sub-threshold or Near-threshold technology with optimal power. The invention may also implement concurrently use of two voltage domains inside a single place and route block. One voltage domain for the “clock tree” buffers and one voltage domain for the other cells at the block. The voltage domain for the “clock tree” buffers that is used is slightly higher than the voltage domain which is used for the other cells. The higher voltage ensures a large reduction of the total number of buffers inside the “clock tree” and the dynamic and static power are reduced dramatically despite the use of slightly higher operating voltage.