| 摘要 |
<p>PURPOSE:To effectively utilize the number of input ports of a microcomputer by inputting a frequency signal corresponding to the state of an input switch to one input port of the microcomputer under the existing state of many input switches. CONSTITUTION:When the input switch 12 is constituted of a three-contact switching type switch e.g., a DC signal is generated from an oscillation means 13 when two contacts (a), (b) of the switch 12 are selected, and the selection of the contacts (a), (b) is inputted to the microcomputer 11 by setting up signals with 'H' and 'L' output levels. When the residual contact (c) is selected, a signal with the specific frequency is oscillated from the oscillation means 13 and the oscillated signal is inputted to an input port 111. Since signals from the switch circuit 12 with plural contacts (a), (b), (c) can be inputted to one input port 111, the number of input ports set up in the microcomputer 11 can be effectively utilized.</p> |
