| 摘要 |
PURPOSE:To suppress a necessary address space within a minimum range by directly changing an address area assigning signal corresponding to an address signal from a CPU and newly assigning each address area in the address space on the basis of the changed result at the change of a memory area or an address area. CONSTITUTION:When an address area in an address space is to be changed, statue ''1'' is written in one bit of an I/O port of an I/O3. In this case, an output signal of a switching means 6 is kept at ''1''. When the CPU1 accesses a prescribed address 5000, and address signal AS (5000) is outputted from the CPU1, an address area assigning signal S (D) different from an address area assigning signal S5 based upon the address signal AS (5000) is inputted to an address area setting means 7, a RAM selecting signal S1 is outputted from the address area setting means 7 to access the RAM2 and the address signal AS (5000) is assigned to the RAM area in the address space. |
