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Altera_Forum
Honored Contributor
Honored ContributorDE2 crystal clock pulse
Hi All, I need to generate a square wave from the DE2 board. I already assigned the DE2 board internal, 50MHz clock to a NOT gate and its output to a GPIO pin and read using an oscilloscope. how...
Altera_ForumHonored Contributor
Honored ContributorAgree with FvM, most likely the problem is with the measurement, not the signal itself.
The length of the ground wire on scope probes means that it is useless for any sort of high speed measurements, you need to reduce the length of the loop that goes from the driver of the signal, to the probe tip, to the probe ground, to the PCB ground and back to the driver. One handy tip I've used is to unscrew the sheath of the scope probe and hold an unbent paperclip across the metal of the probe body to a nearby ground point on the PCB. This massively shortens the length of the ground loop. I hear the blade of a craft knife is even better, because a wide strip of conductor has a lower impedence than a thin wire. Also, reduce the drive strength unless you need it.
