The initial fault universe shall consist of single, permanent, stuck-at-zero and stuck-at-one faults on every logic line (not simply on every logic node) in the
G-logic partitions of
the logic model. A bus, which is a node with multiple driving lines, shall be
considered, for the purpose of fault universe generation, to be a
multiple-input, single-output logic gate. The initial fault universe shall
include stuck-at-zero and stuck-at-one faults on each fan-in and fan-out
branch and the fan-out origin of the bus (see Figure
The fault universe does not explicitly contain any faults within B-logic partitions. However, all faults associated with inputs and outputs of B-logic components either are contained in a G-logic partition or shall be shown to be considered by established test algorithms that are applied to the B-logic partitions.
No faults shall be added or removed by considering or not considering logic model hierarchy. No extra faults shall be associated with any primary input or output line, macro input or output line, or logic line that spans logic partitions where the logic partitions do not correspond to a physical boundary. No more than one stuck-at-zero and one stuck-at-one fault per logic line shall be contained in the initial fault universe.