| 摘要 |
The circuit is applicable to the A and μ Law Type conference communication method. 32 number of the subscriber can be participated in the phone conference using the circuit. The circuit includes a digital mixer (80) for modulating the PCM audio data of the 32 members of subscribers into the linear PCM data and de-modulating the mixed limear PCM data into PCM data of A or μ-Law type, a controller (30) for controlling the digital mixer to mix the wanted channels, providing the attenuation control signal to the mixer when the sum of the audio signals of each channel exceeds certain level, an a/μ law selectro (70) for providing selection data of A or μ law, a logic module (90) for synchronizing the timing of the status data transmitted from the controller and the mixed PCM data by receiving a synchronous signal and a clock signal, an 1-bit static RAM (60) for compensating the delay in the channel/frame by the output control signal of the logic module, and a ROM (40) for storing the monitor program and the group information.
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