| 摘要 |
PURPOSE:To execute the address conversion processing and the address check processing in one step, by executing both processings inthe same timing period. CONSTITUTION:The base address of an access area and an access address are stored in an address base register 3 and an access address register 5 respectively. The complementary value of the difference between the limit address and the base address is stored in an address length register 10. Contents of the register 5 are sent to an adder 6 and an operating part 11 and are added to the contents of registers 3 and 5 respectively. The addition value in the adder 6 is stored in the upper half of a system absolute address register 8, and the contents of the register 5 are stored in the lower half of the register 8. Thus, the contents of the register 8 are converted to a system absolute address. The access address is checked on a basis of presence or absence of the carry output generated as the operation result in the operating part 11. |
