| 摘要 |
PURPOSE:To remarkably improve the noise-resistance, by making data ineffective when an external pulse noise detection circuit is operated during the data transmission and transmitting the same data again. CONSTITUTION:Assuming that a pulse of low level is outputted from an oscillator OSC to a control line SIRQ and a noise is applied on a data bus during the transmission of data. If the noise which has a level malfunctioning data lines D0-D7 and cotrol lines SIRQ and STR, is applied, the noise pulse is given to a control line BUSY to set an FF. When the FF is set, a Q output goes to high level, a transistor TR turns on to keep the control line BUSY to a low level. When data transmission unit SU makes an STO signal to a high level, the transmission and reception units SU and RU read the state of the control line BUSY and the data transmission in this cycle is made ineffective. In the next cycle, the control line BUSY is restored to a high level and the unit SU again transmits the data. |
