| 摘要 |
<p>In an emulation system including first and second peripheral emulators, the second peripheral emulator having a conventional peripheral circuit and an additional peripheral circuit is additionally provided with an input/output switching circuit for switching over the input/output signal between the additional peripheral circuit and a peripheral circuit of the first peripheral emulator. Thus, it is possible to select, as the signal to be supplied to the additional peripheral circuit, either the signal supplied through an external terminal from the first peripheral emulator or the signal outputted from the conventional peripheral circuit, and simultaneously, it is also possible to selectively supply the signal outputted from the additional peripheral circuit, either to the first peripheral emulator through the external terminal, or to the conventional peripheral circuit. Thus, it is possible to access the additional peripheral circuit as the additional function of the peripheral circuit internally provided in the first peripheral emulator. Therefore, a product having an additional function added to the conventional peripheral circuit, can be emulated without changing the interrupt priority order or level. <IMAGE></p> |
