Circuitry for extraction of a transmission clock signal from-modulated data transmissions

Claim 1

In an electronic circuit for extraction of a transmission clock signal from modulated data transmissions, comprising: a local clock producing a local clock pulse signal at a high frequency; a delta-modulation circuit responsive to the data modulated transmissions and the local clock pulse signals and producing a delta-modulated signal in response thereto; a shift register clocked by the clock and responsive to the delta-modulated signal to produce a data word in parallel form; a comparator connected to the shift register and operating in a manner that the comparator produces a logically high output signal when all bits are identical and producing a logically low output signal otherwise; and an interpreting stage responsive to periodicity of the output signals generated by the comparator and producing an extracted transmission clock signal having a periodicity equal to periodicity of the transmission clock signal and being in phase therewith.