| 摘要 |
<P>PROBLEM TO BE SOLVED: To restrict each number of input/output ports of a CPU for detecting kinds of option devices to one bit also in the case where a plurality of the option devices are connected. <P>SOLUTION: An oscillation signal generated by an oscillating part 111 is inputted to resonance circuits 131A-131D possessed by the option devices 130A-130D through connectors 106A-106D connected in parallel to each other. A frequency variable part 112 raises a frequency f of the oscillation signal. A resonance detecting part 105 detects whether or not any of the resonance circuits 131A-131D is in a resonating state by comparing a peak value V3 of a voltage V2 with a reference voltage V4. A resonance frequency detecting part 113 detects a resonance frequency of the resonance circuits 131A-131D from an output V5 of the resonance detecting part 105 and the frequency f. An option device detecting part 114 detects the kind of the option devices 130A-130D from the detected resonance frequency. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
