Patents Represented by Law Firm Blakely, Sokoloff, Talor & Zafman
  • Patent number: 5412697
    Abstract: The delay line separator extracts a clock signal from a combined data/clock encoded signal received over a serial data bus, despite the presence of significant duty cycle distortion. Such distortion affects the width of symbols within received data packets but does not affect the timing between successive rising edges within the received pulse string. To extract the clock signal from the distorted signal, the separator exploits a pre-filter circuit which generates 20-nanosecond pulses synchronized with each rising edge in the received signal. A 20-nanosecond pulse train is transmitted down a delay line having twelve delay elements. Circuits are connected to every other delay element within the delay line for generating 10-nanosecond pulses, synchronized with each rising edge of the pulse train. Outputs from the circuits are combined using an OR gate to yield a 10-nanosecond clock signal.
    Type: Grant
    Filed: January 14, 1993
    Date of Patent: May 2, 1995
    Assignee: Apple Computer, Inc.
    Inventors: Roger Van Brunt, Florin Oprescu