| 摘要 |
PURPOSE:To improve the use efficiency of a memory space by providing a shared memory space which is so constituted that a part of plural memory spaces of the first type can be provided in a memory space of the second type. CONSTITUTION:A processor group 5 has private memory spaces 10-1 and 10-2, and a processor group 6 has private memory spaces 11-1 and 11-2 in positions symmetrical to that of the processor group 5. Each processor decodes an address to determine whether it should access a shared memory space 7 or private memory spaces 10-1, 10-2, 11-1, and 11-2. In this arrangement of the memory space 7, a processor group 5 shares memory spaces 13 and 14 of the shared memory space 7, and the processor group 6 shares memory spaces 12 and 13 of the shared memory space 7. Further, processor groups 5 and 6 share the memory space of the shared memory space 7 as the whole. Thus, a large mem ory space is taken and is maintained as a shared memory. |
