Conclusion
Test of integrated digital circuits - Design For Testability

Testing (and designing for testability) is not an end in itself, but a task designed to help and/or improve production. Testing does not make circuit design easier; on the contrary, design should simplify testing at the end of manufacturing, during maintenance and during operational phases. Any increase in the cost of circuit design is then offset by: lower testing costs during production of the same circuit, lower production costs for the equipment using it, and gains on future circuit sales thanks to better quality, inducing a better brand image and greater customer satisfaction.

The increasing ratio of internal to external bandwidth makes it increasingly difficult (and inefficient) to test a circuit by vector application with external equipment. The trend is therefore towards a shift in the split between external and integrated testing, in favor of integrated...