| 摘要 |
The number of pulses corresponding to numeric keys is changed by connecting external resisters on a keyboard and flash time, make/break ratio and pause time are selected by key operation. The IC includes a key input and scaning logic unit (1) comprising a flash time and make/break ratio selection logic (22), a pause time selection logic circuit (23) and a pulse controller (24) for controlling the number of pulses according to output signals of the pause time selection circuit (23) and keyboard signal, a preset data selection logic circuit (5) for deciding the number of pulse according to a preset data level, and a memory latch and preset data decoder (26) for decoding output data of the preset data selection logic circuit (25).
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