| 摘要 |
PURPOSE:To attain surely the management of number of digits of a dial number, by outputting a key input inhibiting flag during the operation for preventing malfunction due to key input. CONSTITUTION:An address counter 24 counts up a pulse of a prescribed period at each key input or with a redialing signal. An address decoder 25 decodes the content of the counter 24 and outputs an address signal ADR of a memory. A digital memory and a coincidence detecting circuit 26 store the content of the counter 24 and compares the content of the counter 24 with the redialing signal input with the storage content. Flip-flops 21, 22 are reset with a redialing signal RD and output respectively a key input inhibiting flag F1 during the redialing and a redialing key input inhibiting flag F2 after the operation. When the decoder 25 decodes the content of the counter 24 of >= the 2nd digit, the FF21 is reset by a coincidence signal out of the circuit 26. An RST is a reset signal by off-hooking. |
