| 摘要 |
PURPOSE:To carefully detect access to the outside of an area in accordance with an actual program by using plural registers, to which an accessable address range is freely set, to detect the access to the outside of the area. CONSTITUTION:The address range which a program can access is set to plural base registers 20-1-20-n, to which the base address and upper and lower limit addresses are set through a base register setting part 30, with instructions of the program as the object. The set value of one of registers 20-1-20-n corresponding to the base register number in a field 11 of the instruction set to an instruction register 10 is compared with an effective address value which is calculated and determined in an address calculating part 50 based on the base register number, the index register number, and the relative address in fields 11-13, and it is detected by an access to the outside of the area detecting part 60 whether the effective address is on the outside of the address area or not. Since the access to the outside of the area is detected not in the program unit but in the instruction unit in this manner, the access to the outside of the area is carefully detected in accordance with the actual program.
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