Space and time switch for 22 PCM highways

A space and time swich, comprising:

• input means for converting incoming PCM data streams formed of frames of data into parallel streams and multiplexing said parallel streams into one stream;
• control interface means for receiving command data in the form of bytes and transferring said command bytes as a combination of address and data bits;
• first storage means for storing a complete frame of the data transferred within each time-slot;
• second storage means for storing commands from said control interface means;
• output means for receiving a multiplexed stream from said first storage means and converting said stream to a serial stream;
• and
• state control means for influencing operation of said input means, control interface means, first storage means, second storage means and output means.

A space and time switch, comprising:

• input means for converting twenty-two incoming serial PCM data streams formed of frames of data into twenty-two 8-bit parallel streams and multiplexing said twenty-two parallel streams into one 8-bit parallel data stream;
• control interface means for receiving commands in the form of twenty-four bits appearing as three bytes in three separate operations, storing said bytes until all three are ready and transferring said command bytes as a combination of address and data bits;
• a speech RAM storing a complete frame of the data transferred within each time-slot;
• a control RAM storing commands from said control interface means;
• output means for receiving a multiplexed 8-bit parallel data stream from said speech RAM and converting said stream to a serial stream;
• and
• state control means for influencing operation of said input means, control interface means, speech RAM, control RAM, and output means, said state control means controlling readout of the commands from said control RAM, said readout commands becoming addresses for said speech RAM.