| 摘要 |
An external memory is designed as a number of pages each associated with a particular function. The memory is electrically connected to a single circuit in which there is integrated a circuit for generating clock signals relative to PCM system frame and a non-blocking circuit for PCM system switching of one hundred and sixty channels subdivided into five links at a bitrate of 2 Mbits/s. A circuit controls the signalling channels between peripheral channels and the real control unit, with four simultaneous conferences of three users each provided. A PCM system tone generation is included as well as a circuit for signal peak level measurement, and auxiliary circuits for testing the integrated circuits. The whole is controlled by a microprocessor which allows the simultaneous operation of integrated circuits by subdividing the external memory by a time division technique. |
