Clock recovery from data streams containing embedded reference clock values

A digitally implemented clock recovery apparatus for clock recovery from a data stream containing embedded reference clock values, the apparatus comprising:

• a clock reference register operable to store clock reference values received from the incoming data stream;
• a digital comparator operable to compare the stored clock reference values and a locally generated clock reference values, and to provide a control value in response;
• and
• a controlled clock source operable to provide a locally generated clock signal synchronized with the clock reference values in response to the control value, wherein the controlled clock source includes a controllable digital fractional divider operable to receive the control value and a clock input from a digital clock synthesizer.

An improved apparatus for clock recovery from data streams containing embedded reference clock values comprising:

• clock reference storage means for storing clock reference values received from the incoming data stream connected to, input of a digital comparator means, the second input of which is connected to,
• local clock (LC) storage means for storing locally generated clock values provided by a,
• a counter which receives a clock signal from a controllable digital fractional divider controlled by the output of said digital comparator,
• wherein said controllable digital fractional divider receives a control value from said digital comparator and a clock input from a digital clock synthesizer means driven by a fixed oscillator.