| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a memory device capable of preventing correct data or a correct program from being reproduced even in the case of trying to illegally read out the contents of a memory. SOLUTION: When a specific address inputted from a specific address setting circuit 16 coincides with an input address, a coincidence circuit 15 outputs a coincidence signal. A counter circuit 17 outputs a pulse signal in each prescribed number of inputs of coincidence signals. A multiplexer switching circuit 18 switches only the prescribed number of addresses in an output from a multilexer 14 to the error data side outputted from an error data conversion circuit 13. Even when a non-regular user scans the addresses of a memory cell array 12 in the case of trying to illegally read out data, it is difficult to reproduce correct data or a correct program from obtained data because the error data are mixed in the read data in each prescribed period.</p> |
