| 摘要 |
PURPOSE:To simplify the constitution of a titled system by providing a circuit which sends out print data to a printer with an interruption signal, a reset circuit which initializes respective circuits on power-on operation, and a circuit which inhibits the generation of the interruption signal for a specific time. CONSTITUTION:While a power source is turned on and the capacitor C of the reset curcuit 21 is charged, an L-level signal is supplied to a reset terminal to reset a CPU11 and also clear latches 14 and 15, so no signal is transmitted to the printer. When the CPU11 sends out a printer-on command, counters 17 and 18 are cleared and an FF19 is set, so strobe signals (a)-(c) from the printer are supplied as the interruption signal to the CPU11. The FF19 is cleared when the signal is generated right after the power source is turned on, so interruption is inhibited and the printer does not operate, eliminating unnecessary printing operation. On the other hand, the counters 17 and 18 start counting when the printer- on command is generated the specific time after the power source is turned on, and the FF19 is not cleared to allow an interruption, thereby printing specific data.
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