| 摘要 |
PURPOSE:To secure a substantial increment of the memory capacity for RAM by realizing an allotment of the address range equivalent to the address range defined by the output address information of the microprocessor to the RAM. CONSTITUTION:In terminal unit 1, microprocessor 6 undergoes the control of microprocessor control part 7 and is then connected to memory control circuit 5 via address bus 3 and data bus 10. Circuit 5 supplies unconditionally the address information on bus 3 to the address input of RAM9 while receiving ROM inhibit information 4 from part 7. In case the address information on bus 3 is included in the ROM allotment address region shown by memory region setting circuit 2 when no information 4 is received, the address information is applied to the address input of ROM8. And in case the address information is included in other address regions, the address information is sent to the address input of RAM9. |
