| 摘要 |
The output port(PA0-PA3) of the microprocessor(20) is used for the input of the decoder(25) which has the function of decoding up to 16 items(O-F). The port scans the digital switch of the time setting part(30) quickly. The microprocessor(20) confirms the present input level by the pull up resist of the pull up resistor(35) and checks the selected time value. So, within the microprocessor(20), the time is calculated and it compares it with the selected time value. Only when they coincide, the output is made through the output ports(PC0-PC6). After that, the high level is outputted only when the cumulative time value agrees or exceeds the established value.
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