| 摘要 |
PURPOSE:To perform unitarily memory control by a central processing unit by designating an accessible memory area from the central processing unit for each input/output channel and protecting the memory area. CONSTITUTION:A memory protecting device 106 judges whether a selected input/ output channel is going to access to a memory of an area designated beforehand. When it is working correctly, a memory access permission signal 107 is outputted to a memory system 102. When an input/output channel is going to access the memory, it is judged whether the memory address is in the designated area, and the memory access permission signal 107 is outputted only when the memory address is in the area. Accordingly, the memory can be protected scrupulously for each input/output channel. Further, by monitoring the generation of the memory access permission signal 107, an input/output channel having generated troubles can be judged easily and in an early stage. |
