Flip-flop Selection to Maximize TDF Coverage with Partial Enhanced Scan

Abstract

Enhanced scan designs support high coverage TDF testing but with significant overhead. We present a flip-flop selection strategy for partial enhanced scan designs that offers a favorable trade-off between coverage and overhead. Experimental results using commercial ATPG tools show that 60-90% of the TDF coverage benefits of enhanced scan can be achieved at 10-30% of the cost.