| 摘要 |
<p>An integrated circuit is provided, which disables writing to a storage device on the user side once a current is passed therethrough. The integrated circuit (10C) has a flash memory (46) operating as a storage device tofrom which writingerasure is possible when a readwrite enable port (RW) is in a high level. When a power supply (Vdd) is applied to an external power supply input terminal (24), a fuse (18) having a polysilicon interconnection pattern is blown after a set time period by the output of a step up regulator circuit (16). After the fuse (18) is blown, the input of a buffer (20) is fixed to a low level through a resistor (21), so that the readwrite enable port (RW) of the flash memory (46) as the output of an AND circuit (40) is fixed to a low level and the flash memory (46) becomes a read only memory.</p> |
