A unified design methodology for offline and online testing

This article proposes a unified test design methodology for both offline and online testing. The methodology´s purpose is the development of homogeneous test algorithms and test strategies on different abstraction levels of computer systems, from gate level, through register-transfer level, to system level. It uses VHDL design descriptions and provides testing of both separate and combined abstraction levels. The proposed approach is based on disjoining test algorithms from test management. Test management is different for offline and online testing and must have different implementations (test processors) for the two types of testing. At the same time, a test algorithm may be identical for both types of testing. A test processor´s complexity depends on the testing level. For example, at the gate level, implementing the test processor as a circuit is usually desirable. At higher levels, it should be implemented as a coprocessor in a computer system processing element. The system level of a distributed computer system based on the cluster principle requires an organization of test server and test clients inside the test processor