Improving Glitch Precision

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If you're using a target with its own clock source, it's possible to set up the glitch module to have a higher resolution. The steps to do this are:

  • Set the CLKGEN input source to `EXTCLK`.
  • Set up the mulitply and divide values to make CLKGEN faster than the external clock (for example, Multiply = 10 and Divide = 1). Keep in mind that extremely clock speeds won't work.
  • Set the glitch module's clock source to CLKGEN.

Now, one period of the glitch module's output will be a fraction of the target's clock period.

This overclocked glitch module is best used with the `Enable Only` output mode, which generates a single pulse that can last for many clock cycles. The `Ext Trigger Offset` and `Repeat` values are in terms of the glitch module's clock, so the pulse's start and end times can be tuned by fractions of a target period.