Siemens Corporation

Sam Liang

Deepak R Muzumdar

Theodore W Wagner

Digital telephone apparatus suitable for use as a subscriber station as well as for an attendant console. The telephone apparatus is connectable for full duplex communication with a four wire telephone transmission line. The telephone apparatus is capable of transmitting PCM speech data and/or digital data from a digital data interface to a peripheral data system. The telephone apparatus comprises an internal data bus to which are connected a digital transceiver, a sync/signalling generator, a serial frame synchronizer and at least one codec/PCM filter. The transceiver transmits and receives digital data to and from the telephone transmission line. The sync/signalling generator repeatedly supplies an 8 bit first data word to the internal data bus containing a binary synchronizing code and a signalling code. Simultaneously, the serial frame synchronizer repeatedly receives from the data bus and decodes an 8 bit first data word containing a synchronizing code and a signalling code. The codec/PCM filter repeatedly receives from and transmits to said internal data bus 8 bit PCM voice samples as additional data words immediately following the first data word. A microcomputer, including a number of input/output devices, receives successive signalling codes from the serial frame synchronizer and repeatedly transmits signalling codes to the sync/signalling generator for communicating with the telephone exchange to which the apparatus is connected.

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Deerfield Beach, FL, United States of America

Sam Liang