Here, we consider deterministic testing of combinational and sequential circuits. The basic methods for combinational circuits 1 assume combinational faults (i.e., faults such that the circuit remains combinational). If a sequential fault affects a combinational circuit, the methods for sequential circuits are relevant to it.

This chapter provides the basis for answering the following type of questions: 1) given a fault, find a test vector (combinational circuit) or a test sequence (sequential circuit) to detect it; 2) given a set of faults, find a test set (combinational) or a test sequence (sequential) to detect every fault in the set. For a set of faults, the problem of relations between faults arises.

The two basic principles are the comparison between faulty and fault-free circuits, and propagation of an error through a sensitized path. They are illustrated by simple examples. Algorithms based on these methods do exist and are used in the Automated Test Pattern Generator (ATPG).

Section 3.1 and Section 3.2 are respectively dedicated to combinational and sequential circuits.