Full chip false timing path identification:: Applications to the PowerPC™ microprocessors

Static timing analysis sets the industry standard in the design methodology of high speed/performance microprocessors to determine whether timing requirements have been met. Unfortunately: not all the paths identified using such analysis can be sensitized. This leads to a pessimistic estimation of the processor speed. Also, no anlount of engineering effort spent an optimizing such paths can improve the timing performance of the chip. In the past, we demonstrated initial results of how ATPG techniques can be used to identify false paths efficiently [l]. Due to the gap between the physical design on which the static timing analysis of the chip is bused and the test view on which the ATPG techniques are applied to identify false paths, in many cases only sections of some of the paths in the full-chip were analyzed in our initial results. In this paper; we willfully analyze all the timing paths using the ATPG techniques, thus overcoming the gap between the testing and timing analysis techniques. This enables us to do false path identification at the full-chip level of the circuit. Results of applying our technique to the second generation G4 PowerPC (TM) will be presented.