| 摘要 |
<p>PURPOSE: To improve security by limiting the address range of a memory to be accessed by an information processing program by setting the value of a bit at a fixed value together with the generation of fixture execution information. CONSTITUTION: Plural information processing programs are stored by a storage means, the address outputted to an address bus 17 designated by a program counter 16 and the instruction codes of the stored information processing programs are outputted to a data bus 18, the instruction codes outputted to the data bus 18 are read by an instruction processing part 15, and instruction processing is performed based on the instruction codes. When the fixture execution information is generated, the value of one bit among plural bits consisting of the program counter 16 is turned to the fixed value by a fixing means at least. Therefore, the range of the address designated by the program counter 16 and outputted to the address bus 17 is limited, and the range to be accessed by the information processing program is limited.</p> |
