Design For testability, DFT, BIST,...

DFT design for testability: Testing Basics • Testing and debug in commercial systems have many parts – What do I do in my design for testability? – How do I actually debug a chip? – What do I do once I’ve debugged a chip? • Two rules always hold true in testing/debug – If you design a testability feature, you probably won’t need to use it • Corollary: If you omit a testability feature, you WILL need to use it – If you don’t test it, it won’t work, guaranteed Two Checks • There are two basic forms of validation – Functional test: Does this chip design produce the correct results? – Manufacturing test: Does this particular die work? Can I sell it? • What’s the difference? – Functional test seeks logical correctness • >1 year effort, up to 50 people, to ensure that the design is good – Manufacturing test is done on each die prior to market release • Send your parts through a burn-in oven and a tester before selling them. Testing Costs Are ...