| 摘要 |
PURPOSE:To easily change an address map at the time of executing a program, by performing memory mapping by the RAM of a program, and switching the I/O terminal of the RAM to a data bus or a peripheral device. CONSTITUTION:When the execution of the program stored in a ROM3 is started, firstly, the space of a programmable decode RAM5 is selected, and also, a bus switching device 6 becomes active. Next, chip select on a signal line 13 prepared in advance is set at a select state, and data to be mapped is written. And when programmable mapping space is selected, a chip selector 7 becomes active, and the chip select corresponding to written data is selected. Also, when the memory mapping is changed, it can be changed by a software similarly as in the above stated manner.
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