| 摘要 |
PURPOSE:To remarkably simplifying the processing for accessing additional information, and also to utilize an idle area on an RAM for storing the additional information, by placing a constitution control information storing part and an additional information storing part so as to correspond to each other. CONSTITUTION:An address which has stored corresponding information relating to a memory constitution unit in the first storage area 10, and an address which has stored additional information corresponding to the constitution unit concerned in the second storage area 11 are accessed, respectively, by holding the contents of a register 8 at a prescribed value, and setting an access area switching bit part 9 to logical ''0'' or ''1''. When accessing a main storage device in a normal state, the switching bit part 9 is placed in a state of logical ''0'', and in accordance with contents of a register part 4 by which a part of a real address is set, one in the first storage area 10 is accessed. Subsequently, the real address concerned is converted to an address showing a memory constitution unit to be accessed, and said access is executed. |
