On-chip spread spectrum characterization

An integrated circuit for on-chip spread spectrum characterization, the integrated circuit configured to carry out the steps of:

• obtaining, from a skitter circuit, skitter data comprising a spread width corresponding to an amplitude of a spread of a spread spectrum clock signal;
• setting an offset pointer to a center of the spread width corresponding to the amplitude of the spread;
• retrieving, for each of a number of reference clock cycles, edge data indicating a location, within the spread width, of an edge of the spread spectrum during the reference clock cycle;
• incrementing, using the edge data, an offset counter for each reference clock cycle during which the edge of the spread spectrum crosses the offset pointer;
• and
• calculating a frequency of the spread spectrum using the offset counter and the number of reference clock cycles.

A computer program product for on-chip spread spectrum characterization, the computer program product disposed upon a computer readable medium, the computer program product comprising computer program instructions that, when executed, cause a computer to carry out the steps of:

• obtaining, from a skitter circuit, skitter data comprising a spread width corresponding to an amplitude of a spread of a spread spectrum clock signal;
• setting an offset pointer to a center of the spread width corresponding to the amplitude of the spread;
• retrieving, for each of a number of reference clock cycles, edge data indicating a location, within the spread width, of an edge of the spread spectrum during the reference clock cycle;
• incrementing, using the edge data, an offset counter for each reference clock cycle during which the edge of the spread spectrum crosses the offset pointer;
• and
• calculating a frequency of the spread spectrum using the offset counter and the number of reference clock cycles.