| 摘要 |
PURPOSE:To display accurately the transmission/reception state of a line with simple constitution by providing a register holding the line number of a line in making transmission/reception and a display means displaying the line during transmission or reception. CONSTITUTION:When the interruption from a line is informed to a microprocessor 11, a microprogram discriminates it as transmission request, reception request or others, and when it is the transmission request interruption, the data to be transmitted next is prepared, it is used as the line state display to discriminate whether the display is effective or not and if effective, a transmission display command is given together with the character transmission command. If ineffective, only the character transmission command is given. When the reception request is given, after the character reception command is given and the reception display command is given if effective. When the microprocessor 11 gives the transmission display command or the reception display command, the content of the command is stored in an instruction storage register and its content is transmitted to a command decoder 17 as a command bus signal 16. |
