Calculating error of measurement on high speed microprocessor test

Accuracy and precision are desirable properties of any test process. Understanding test process capability can help ensure that high speed microprocessors are binned at their proper speed. This paper discusses a practical example of how a designed experiment was used to determine the test process speed sorting error of measurement of the Alpha AXP, the industry's fastest microprocessor, tested at Digital Equipment Corporation's Hudson, MA manufacturing site. Knowing error of measurement allowed effective guardbands to be established to guarantee specified performance in the context of the supplier's and consumer's risks. A series of test process improvements resulted from the follow-up work suggested by the experiment.