Character framing circuit

A digital system for receiving successive data characters transmitted as contiguous characters forming synchronous serial data which is a continuous sequence of digital data bits, said system comprising:

• (a) shift register means comprising a plurality of serially coupled shift register stages each, except for the last stage thereof, having an output connected to the input of the succeeding stage, and the first stage thereof being coupled to a source of said serial data, and each stage being coupled to a source of clock pulses, said clock pulses being synchronized with said digital data bits;
• (b) logic means for generating a control code prefix and for loading said control code prefix into one of said shift register stages;
• (c) means for shifting said control code prefix to a second one of said shift register stages and for coincidentially shifting serial data into said shift register means in synchronism with said source of clock pulses;
• (d) means for detecting said control code prefix in said second shift register stage and for generating a signal;
• (e) means responsive only to said signal for indicating that said serial data is occupying said shift register means as a received serial data character;
• and
• (f) control means coupled to said logic means and to said source of clock pulses and responsive to the occurrence of said signal for causing said logic means to generate and load said control code prefix.