| 摘要 |
PURPOSE:To freely utilize an input/output peripheral function over a wide range and to facilitate debugging work by making the input/output port of a one-chip microcomputer into one-bit configuration and providing extension circuits. CONSTITUTION:A one-chip microcomputer 1 is composed of a CPU 2 for performing arithmetic, A/D converter 3 for fetching analog data, D/A converter 4 for outputting analog data, input/output port 5 for inputting/outputting digital data, timer 6 for requesting interruption in a fixed cycle, ROM 7 for storing a control program and RAM 8 for temporarily storing data. Further, extension circuits 10, 11 and 12 are provided to extend one piece of analog or digital data inputted and outputted from the microcomputer 1 to plural pieces of data. Thus, the number of input/output terminals at the microcomputer 1 is considerably decreased, the number of data to be extended can be easily changed by increasing/decreasing idle signal lines A1-A3, and this device can be economically applied over the wide range. |
