| 摘要 |
PURPOSE:To contrive to protect a bit of memory information, by collating a prescribed bit of cipher information inputted corresponding to a bit of recording address information, with the bit of cipher information held in a memory device in advance, and deciding the feasibility of readout. CONSTITUTION:When the bit of memory information stored in the memory device 1 is read out, the bit of recording address information in a main memory part 2 is inputted to the main memory part 2 through a information line 101, and also, it is inputted to a deciding part 5. To the deciding part 5, an arbitrary bit of cipher information to be attached on the memory device 1 is also inputted through an information line 102. And only when a prescribed collating condition is satisfied among the bit of recording address information, the bit of cipher information, and the arbitrary bit of cipher information written in a cipher memory part 4 in advance, at the deciding part 5, a specific control signal for a gate part 3 is outputted. And the bit of memory information corresponding to the bit of recording address information read out from the main memory part 2 through the gate part 3 is outputted through the information line 102. |
