| 摘要 |
The ring circuit and the melody circuit are integrated to one chip by realizing the ring circuit using MOS transistors. The ringer includes an operating threshold voltage generator for generating operating start voltage at a certain source voltage level, a frequency selector for generating ring enable signal at a certain frequency, a cord generator for generating code frequency using a first oscillated frequency, a tone generator for generating scale frequencies using a second oscillated frequency, a rythm generator for generating rythm using the oscillated frequency, a ring-melody data ROM for providing control data to the code, the tone and the rythm generator, a controller for controlling address signals transmitted to the ring-melody data ROM, and an envelope output unit for outputting melody signal. |
