DIALER CIRCUIT AND CONTROL METHOD FOR MELODY CIRCUIT

摘要

The dialer circuit (100) for controlling a melody circuit (200) has a hold circuit. The hold circuit (20) receives on-hook dial input signal, hook-switch input bar signal and hold input signal, and provides the key inhibit bit signal to a key input latch section (11). The key input latch section latches a number of key input signals into the predetermined pulse signals. A dial circuit (12) controls the key input latch section and simultaneously executes the dialing according to the pulse signals. The hold circuit includes two T flip-flops for producing hook output control signal and hold output signal, and a reset circuit for resetting two T flip-flops and producing the chip enable signal.