81 - Introductory Hardware Testing
Defects exist in almost any IC produced.
All produced ICs should be tested and faulty ones discarded
A test is a set of tasks carried out to check if something is working properly
Proper sequence of values
System being tested
System to which we compare a test SUT
System that compares test results
Equipment that automates the testing process
Patterns are generated by algorithms ad-hoc implemented in the ATPG - Automated Test Pattern Generation environments
Methodology that revolves around designing a system such that it is testable in the first place
At design time introduce two modes, normal functional mode and test mode, and adopt a scanning technique
Serial interface that allows access to special embedded logic in most chips
In a processor or BGA (Ball Grid Array) /PGA (Pin Grid Array), this standard adds additional pins (TAP ports), an additional internal register and the TAP controller.
Vastly adopted due to benefits from testing logic not needing extra stuff
System performs normally but has to be taken down for tests
Test is performed while system is running
System designed so that it can self-correct faults