The effectiveness of the scan test and its new variants

Many industrial experiments have shown that the very simple and time-efficient Scan test detects many unique faults. This paper shines a new light on the properties of Scan test; such properties will be evaluated using industrial data. In addition, it will be shown that many faults in a memory, which are not in the cell array, are detectable using the appropriate read-write sequences. The traditional version of Scan test performs ´some´ of such read-write sequences, but lacks the capability of performing all of them for both the ´up´ and the ´down´ address orders and the ´0´ and the ´1´ data values. Therefore a new set of scan based tests are proposed to fill that vacuum.