| 摘要 |
PURPOSE:To attain normal dial tone transmission even with dial input operation before the arrival of a dial tone by storing a dial number from a dial key in a prescribed memory, and executing actual dial transmission under the condition of the detection of the dial tone. CONSTITUTION:When the dial number from the dial key is inputted, a CPU 110 stores the number in order at a dial transmission memory the write and the read of which is controlled by a FIFO system in memory 113. As for a dial transmitting process, it is checked whether data exist or not at a dial data register for the first, and when it is found, a transistor Q8 is conducted, only in case that the dial number to be transmitted is the first digit, and the detection of the dial tone is executed by a dial tone detecting circuit 109. After the dial tone is detected, a dial signal is transmitted actually to a telephone line. Lastly, the memory shift process of the FIFO is executed to transmit the second digit and after of the dial number consecutively in order.
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