| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the processor of another system from being destroyed excepting for a write permitted area by providing an address generation part for generating the address of the write permitted area on the memory board of processor of the other system. SOLUTION: When a CPU 2 outputs any address excepting the write permitted area of a memory map, the high order of that address is exchanged with the data stored in a register 5, and a separate address is generated, stored in the register and outputted to a system interface part 7. In this case, since the data to be stored in the register 5 are fixed by a short pin or any corresponding method, the contents in the register 5 are not changed by the malfunction of the CPU 2 or the runaway of a software. Thus, even if the CPU 2 outputs any address excepting the write permitted area of processor of the other system because of the malfunction of the CPU 2 or the runaway of the software, an address generation part 6 translates that address to an address for accessing only the write permitted area of processor of the other system.</p> |
