Heading off test problems posed by SoC

On top of that, test software faces new kinds of faults stemming from the submicron feature sizes and escalating frequencies. For those faults, traditional ATPG test patterns, which usually target static stuck-at faults only, are no longer sufficient. Adding functional patterns in an attempt to catch the newer faults is an exercise in futility. Better to grade the initial set of functional patterns to determine which faults escape, then create ATPG patterns to catch the missing faults.