| 摘要 |
PURPOSE:To ensure the common control through a communication control part for both a circuit adaptor having an FIFO memory and a circuit adaptor having no FIFO memory, by detecting the underrun of transmission through a universal receiver transmitter (URT). CONSTITUTION:When a control circuit 7 detects the idle state of an FIFO memory 6, the transmission of data is forcibly indicated to a URT5 which is so far inhibited for the trasmission of data. Then a transmission underrun detecting circuit of the URT5 works if the next transmission character is not transmitted. Thus the detection is set for the transmission underrun inside the URT5. As a result, it is possible to apply a display method for transmission underrun which is equal to the circuit adaptor using a URT that uses no FIFO memory. Thus an upper communication control part 2 can give the same control to both a circuit adaptor having an FIFO memory and a circuit adaptor having no FIFO memory. |
