| 摘要 |
<p>PURPOSE:To provide a one-chip microcomputer which is capable of performing an input/output access from both of a one-chip microcomputer side and a main CPU side. CONSTITUTION:A one-chip microcomputer 5 is provided with a control bus 5a for an internal data signal, an address signal and a chip select signal and this is connected with an outport 12 in which double system clock signal is inputted, an import 13 in which 2 series enable signals are inputted and bus controller 6 performing a control operation. A bus controller 6 is connected with a control bus 6a for an external data signal, an address signal, a chip select signal and a read/write signal, and the one-chip microcomputer 5 is connected with a main CPU 1 controlling the operation of an operating system and with an I/O part 4 which is used for the direct access operation via the bus 6a.</p> |
