摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of testing the operational margin of an information storage device having marked random variations, and an information storage device having the function of self-diagnosing the operational margin. <P>SOLUTION: The test method includes testing an information storage device including a plurality of memory bits as the test condition is set so as to be outside a range of conditions that may be presupposed in real use of the information storage device and counting the number of memory bits that fail in operation. The test method also includes verifying the size of the operational margin of the information storage device based on the count value. The test condition is made severe and the reference value is set to a fairly large value to enable the operational margin against the noise to be tested highly accurately. <P>COPYRIGHT: (C)2011,JPO&INPIT |