The testing of mixed analogue/digital customised circuits

The development of customised circuits has moved the problem of testing a system from the test engineer to the customised chip designer. The experience gained by the designer in producing testable digital customised circuits, could be extended to the `design for testability´ of analogue or customised circuits. The costs of providing a measure of testability on the chip can be balanced against the costs of external test equipment and the consequently higher skill level required of the testing operator. Additionally, the provision of on-chip tests circuits for the digital components of a mixed system allows the system to be tested at its maximum operating speed. This paper and talk considers the testing of customised devices and the test strategy adopted, including some circuit examples and a summary of the results