Hardware Reference
In-Depth Information
P
1
SNRB
P
2
f
SNRB
Fig. 3.16
Type-I tests
SNRB
P
1
g
f
P
2
Fig. 3.17
Type-II tests
SNRB
P
1
SNRB
g
f
P
2
SNRB
Fig. 3.18
Type-III tests
During the process of path extension information on (b,f) pairs is used to guide the
path extension. Recall that all paths through a (b,f) pair are untestable. This is il-
lustrated in Fig.
3.19
for Type I and Type IV tests. Each time the current subpath
is extended a unique subpath through a FFR is chosen such that the extended path
does not contain any (b,f) pairs.
Methods to generate compact test sets that attempt to activate and detect TDFs
through largest delay paths have been proposed and a sketch of the method in
Wa n g
et al. (
2008
b) is given next. The method in
Wang et al.
(
2008
b) first finds a testable
