| 摘要 |
PURPOSE:To protect a function so as to be well-adapted to an attribute of a data, b constituting the titled device so that a write data cannot be read out of a memory circuit, unless a cipher key data which is inputted at the time of write is inputted to a pseudo random pattern generating circuit at the time of read-out. CONSTITUTION:A write data 10 is converted to a serial write data 14 by a parallel-serial converting circuit 2, and inputted to an exclusive OR circuit 6. Also, a pseudo random pattern 13 which is generated by pseudo random pattern generating circuit 8, based on a cipher key data 12 is inputted to the exclusive OR circuit 6. An output signal 15 of the exclusive OR circuit 6 is stored in a memory circuit 1. On the other hand, at the time of read-out of a signal, a read-out signal 17 of a memory circuit 1 and the pseudo random pattern 13 are inputted to an exclusive OR circuit 7. Subsequently, an exclusive OR output (series signal) 19 is converted to a parallel signal, and outputted as a read-out data 11. |
