| 摘要 |
PURPOSE:To efficiently use an input/output termianl for data transfer between a CPU and an external peripheral unit by selecting data representing the operating states of functions in a CPU or plural peripheral units or transfer data in a means which performs data transfer by a selective discrimination signal outputted from a peripheral unit selection means. CONSTITUTION:It is selected and judged whether or not read/write destination on the peripheral units 21,22 by the CPU 20 is an external peripheral unit 37 by the peripheral units 21,22 in the inside of a single chip microcomputer corresponding to the value of peripheral unit selective discrimination signals outputted from the plural peripheral units 21,22 and the selective discrimination signal is outputted. The data representing the operating states of the functions of the CPU 20 or the plural peripheral units 21,22 or the transfer data in the means which performs the data transfer is selected by the selective discrimination signal. Thence, the data transfer of the data selected by a data selection means and that from the peripheral unit 37 outside the single chip microcomputer to the CPU 20 are performed. Thereby, it is possible to use the input/output terminal used in only the data transfer in the output of the data representing the operating state in the inside. |
