| 摘要 |
<p>PURPOSE:To find out inconvenience before the malfunction of a system occurs by detecting the volatilization defect of electrically erasable read-only memory by incorporated ultraviolet rays. CONSTITUTION:Read out ROM data Di of low level, and the output signals Zi of high levels of a detection sense simplifier 5 and a detection inverter 6 are inputted to an exclusive OR gate 7 that is a detection signal circuit, and an output signal X is sent out. In such a case, since the output signal X is the exclusive OR of the read out ROM data Di and the output signals Zi of the detection sense simplifier 5 and the detection inverter 6, the output signal of the exclusive OR gate 7 is of low level when an EPROM 2a shows the curves A, C of characteristics (m),(n), however, the output signal X goes to the high level when it shows characteristic (p). Therefore, the EPROM can be detected only when the EPROM 2a is volatile.</p> |
