An Investigation of Possibilities of Improving Random Test Generation for Non-scan Sequential Circuits

Application of Preselection of Test Subsequences in Sequential Test Generation for Functional Delay Faults

“…Some relevant papers [3][4][5][6][7][8][9][10], in which various problems of testing of non-scan synchronous sequential circuits are researched, were published in last few years.…”

“…The possibilities of improving random test generation for at-speed testing of non-scan synchronous sequential circuits are explored in [7]. Based on research of distribution of "1" in randomly generated test pattern there is suggested a guidance for management of test generation process.…”

“…A test subsequence S detects the functional delay fault fd i if the subsequence S satisfies all three mentioned at the beginning of this section conditions: 1. the circuit is brought into state, required for activation of fd i ; 2. the functional delay fault fd i is activated; 3. the effect of fd i is propagated to a primary output. According described in [6,7] approaches the test generation process proceeds in following way. The whole particular subsequence S k is generated randomly, then using fault simulation the set of functional delay faults that S k detects is defined, and if S k detects any not yet detected faults, S k is included into resulting test sequence.…”

“…Random test sequences may be used for at-speed testing as well as for simulation-based design verification [3][4][5][6][7]. The presented in [5,6] research shows that functional tests designed using random test generation exhibit better transition fault coverages than tests produced by deterministic ATPG tools.…”

“…The presented in [5,6] research shows that functional tests designed using random test generation exhibit better transition fault coverages than tests produced by deterministic ATPG tools. The main drawback of presented in [4][5][6][7] methods is their high computational cost. Therefore, in this paper we are going to propose an approach that allows to speed-up the test generation process.…”