Sequential test generation with reduced test clocks for partial scan designs

Abstract

Partial scan design technique is often preferred to full scan because the use of smaller number of scan flip-flops leads to less performance degradation and less overhead. However, the number of clocks required to apply a test vector is proportional to the number of flip-flops in the scan path whenever scan is performed. This tends to increase the test application considerably. In this paper we presents an algorithm to generate a test with fewer test clocks for partial scan designs by using sequential test generation and scan strategies. The objective is to find a test that requires less test clocks while achieving high fault coverage. The algorithm, Test Application time Reduction for Partial scan design (TARP), is implemented and tested on a set of ISCAS sequential benchmark circuits. The algorithm produces a test with substantial reduction in the number of test clocks, compared to a test in which each test vector is associated with a scan operation. >