| 摘要 |
PURPOSE:To hold the security of a software by converting a mutual connection of plural address signal lines for designating an address in a memory. CONSTITUTION:The subject device is provided with a control signal line 1, a connection converting circuit 2 and a program counter 5. When a control signal 1 is '0', an output of a program counter 5 is selected as an address of a memory 6, the contents of an address designated by an address signal line are outputted from the memory 6, fetched by an instruction register 7, and an instruction corresponding to its contents is executed. When the control signal 1 is '1', with respect to an address inputted from an external terminal, addresses C0 - Cn converted by an address signal connection converting circuit 2 are selected, outputted to an address signal line, and the contents of an address designated by the address signal line are outputted from the memory 6, and outputted to an external terminal through an output circuit 8. In such a way, the correspondence of an address and memory data cannot be understood unless a conversion rule of the address is known, the secrecy of the contents of the memory can be kept. |
