| 摘要 |
PURPOSE:To set freely the range of a shared address, by providing an address data latch and a bank address latch, comparing the address data on an address bus with the data on an address data latch and then selecting a bank address in accordance with the coincidence or dissidence obtained from said comparison. CONSTITUTION:A shared address for redundance, etc. of each bank is set by latching a desired address sent via a data bus to an address data latching circuit 1. An upper address corresponding to the page of the said address is compared with an address given from an upper address bus. Then an inhibiting circuit 4 is controlled via a data selector 5. The address latched to the circuit 1 is selected when the coincidence is obtained from the above-mentioned comparison. While the address latched to a bank address latching circuit 2 via a data bus is selected when the dissidence is obtained. Thus a bank address is delivered from the circuit 4. In such a way, the range of a shared address can be freely set for switching of memory banks. |
