Test circuit and methods for speed characterization

Abstract

A system and method for efficiently performing timing characterization of regions of an integrated circuit. An integrated circuit has monitors distributed in different physical regions across its die. Each monitor includes timing characterization and self-test circuitry. This circuitry includes one or more tunable delay lines used during timing measurements. The circuitry verifies the tunable delay lines are defect free prior to the timing measurements. If defects are detected, but tunable delay lines may still be used, a scaling factor may be generated for a failing tunable delay line. The scaling factor may be used during subsequent timing measurements to maintain a high accuracy for the measurements. The timing measurements may determine a particular physical region of the die provides fast or slow timing values. The resulting statistics of the timing measurements may be used to change an operational mode of the IC in at least the particular region.