Design for test definition
Design for test is a concept which means your chip is designed in such a way that testing it is easy. Test logic plays two roles. First, it helps
Design for test is a concept that means your chip is designed in such a way that testing it is easy. Test logic plays two roles. First, it helps debug a chip that has design flaws. Second, it can catch manufacturing problems. Both are particularly important for ASIC design because of the black box nature of ASICs where internal nodes are simply not accessible to you when there is a problem. These techniques are also applicable to CPLDs and FPGAs, many of which already have built-in test features. The following DFT techniques allow for better testing of a chip. While not all of these techniques need to be included in your design, those that are needed should be included at design time. DFT techniques should be taken into account during the design process rather than afterwards. Otherwise, circuits can be designed that are later found to be difficult, if not impossible, to test.