Electrical Testing for Design Verification and Operating Margins

The MOS dynamic RAM presents an extreme example of the problems inherent in testing complex integrated functions. Establishing that a dynamic RAM design is operating as its designer intended under all permitted operating conditions, is a monumentally difficult task. Historically, subtle problems have only come to light when large scale use of a particular part is already established. It is then of little consolation that a supposedly new problem is often found to be closely related to one in an earlier generation of part.