Method for optimizing scan chains in an integrated circuit that has multiple levels of hierarchy

摘要

A method for optimizing scan chains in an integrated circuit that has multiple levels of hierarchy addresses unlimited chains and stumps and separately all other chains and stumps. Unlimited chains and stumps are optimized by dividing an area encompassed by the chains and by a start point and an end point of the stump into a grid comprised of a plurality of grid boxes, and determining a grid box to grid box connectivity route to access all of the grid boxes between the start point and the end point by means of a computer running a routing algorithm. All other chains and stumps are optimized randomly assigning to a stump a chain that can be physically reached by that stump and adding an additional chain to that stump based on the number of latches in the additional chain, its physical location, and the number of latches already assigned.