Patent ID: 6996791
Filing Date: 2006-02-07
Classification: G01R

Abstract:
1. A method of generating a set of scan diagnostic patterns for diagnosing fails in a set of scan chains comprised of scan chain latches, comprising: (a) selecting a group of scan chain latches from said set of scan chains, said group of scan chain latches including all or some of said scan chain latches; (b) selecting a pattern from a set of test patterns; (c) determining a number of lateral insertions of said pattern selected from said set of test patterns; (d) determining a number of new lateral insertions that said pattern selected from said set of test patterns would add to said set of scan diagnostic pattern and adding said pattern selected form said set of test patterns and a corresponding new insertion count to a count list; (e) repeating steps (b) through (d) until all patterns of said set of test patterns have been selected; (f) selecting a pattern from said count list; (g) adding said pattern selected from said count list to said set of scan diagnostic patterns; and (h) repeating steps (b) through (g) until there are a predetermined number of patterns in said set of scan diagnostic patterns.