Path delay faults and ENF

Simplification of fully delay testable combinational circuits and finding of PDF test pairs

“…The percentage of such sub-circuits among all ones was calculated (forth column of Table 2). We appreciated the complexity of the circuits obtained from the Shared ROBDD [9] by covering internal nodes with sub-circuit of Fig. 3 and the circuits obtained by the method suggested here.…”

“…New synthesis method of fully delay testable circuits is suggested that as a rule derives more simple circuits of this kind than in [9]. The simplification is based on multiplications of sub-circuit ROBDDs (these operations have the polynomial complexity).…”

“…Find all prolongations and consequently all products containing the literal x i corresponding to the beginning of the path α. These products comprise a set K α [9]. Note that the products of the MSoP that contain the literal i x corresponding to the path opposite to α have the same sub-product k ε .…”

“…It is necessary to justify its application for the circuits that originate MSoPs instead of ReedMuller expressions in [7]. In [9] …”

“…In [9] path delay faults are considered as temporary stuck-at faults of the corresponding ENF literals. This means that all literals satisfying to the same path are changed for the same constant.…”