PCM Signal processor

Claim 1

A pulse code modulation (PCM) signal processor for extracting signal processor control words from a serial PCM data stream also containing error detection and correction words, said PCM signal processor comprising: serial-to-parallel converter means for converting said serial PCM data stream into a parallel form, said serial-to-parallel converter means including terminals for outputting said signal processor control words and said error detection and correction words; error detecting means responsive to said control words and said error detection and correction codes and connected to said serial-to-parallel converter means terminals for forming an error signal having a first state indicating the presence of an error in said control words and a second state indicating the absence of an error in said control words; first means coupled to said serial-to-parallel converter means for storing first signal processor control signals from said signal processor control words when said error signal is in said second state and for preventing the storage of said first signal processor control signals when said error signal is in said first state; and second means connected to said serial-to-parallel converter means for storing second signal processor control signals from said signal processor control words when said error signal is initially in said first state and subsequently in said second state and when said second signal processor control signals from signal processor control words of two successive PCM data streams are equivalent, said second storing means thereby reducing the chance of erroneous operation by the receipt of random errors in PCM control signals by ensuring that second signal processor control signals be the same in two successive PCM data streams before storage of said signals.