Program-Controlled Memory Test System

The test system provides facilities for determining the range of satisfactory operating parameters of a memory with high accuracy, in a short time, under program control. The system performs its overall control by a miniature computer; it makes memory write-and readout tests, judges the quality while changing various electrical conditions in the memory equipment, and displays the operating area with variation of the parameters as a graph on an X-Y plotter and a cathode-ray-tube (CRT) screen. Among its features, the system provides means for setting the logic levels for measurement, simultaneously setting up many parameters, processing the measured data through arithmetic operation, and in addition allows flexibility in the output methods as well as opportunity for expansion of the measuring system. Two programs are available for the boundary area tracing and the complete area scanning through the use of an algorithm featuring high measuring efficiency and stability. Development of the present system has made it possible not only to evaluate memories in detail but also to gather valuable data for the design of memories.