| 摘要 |
<p>PURPOSE:To use a bit defective product intentionally for a user by activating the bit defective product identifying circuit for the bit defective product at a manufacturer side, perceiving the product used by the user as the bit defective product and activating a bit defective product operating circuit at the user side. CONSTITUTION:In a flash EEPROM. the bit defective product identifying circuit 29 controlling a control signal buffer 14 so that the operation of a circuit part 500 writing data, reading the data and erasing the data to a memory cell array is prohibited regardless of an external control signal CE and the bit defective product operating circuit 30 releasing the prohibition of the operation of the circuit part 500 are provided. Both the bit defective product identifying circuit 29 and the bit defective product operating circuit 30 are constituted so as to be activated by the user side or the manufacturer side after manufacturing the flash EEPROM.</p> |
