| 摘要 |
PURPOSE:To attain the prefetch of a CPU and to increase processing speed by storing an independent operating mode in plural memory banks and selecting the memory bank, which is accessed by the CPU, with a selecting switch. CONSTITUTION:In correspondence to the condition of an output terminal I/O1 and a switch SW1 in a CPU 1, either a ROMa 2 or a ROMb 3 is made effective. Namely, when the terminal I/O1 is L, regardless of the turning-on/off of the switch SW1, a chip select terminal CS1 is selected and the CPU 1 is connected to the ROMa 2. When the terminal I/O1 is H and the SW1 is turned off, the ROMa 2 is selected and when the SW1 is turned on, the ROMb 3 is selected. |
