| 摘要 |
<p>PURPOSE:To eliminate a test unexecuted area by compulsorily causing the function of a lacking voltage detecting part in the power source control circuit of a RAM card to be invalid from an external part at the time of a test, etc. CONSTITUTION:A control input terminal 22 is provided to a lacking voltage detecting function part 13, and at the time of testing the read/write action of the RAM card, it is made possible to execute a control to cause the lacking voltage detecting function of its own to be invalid. It is made possible to execute the test of the read/write action of the RAM card in the area of a lacking detecting voltage 4.4V or below, for example, from 4.2V to 5.5V, and by overlapping with the area of 4.4V-3V of a standby function, the test unexecuted area is eliminated. Thus, at the time of testing the read/write action, the lacking voltage detecting function is compulsorily made invalid, and it is made possible to operate a memory chip from the part of the original standby area up to 5.5V.</p> |
