My strong advice would be to return those caps by a dedicated, isolated track to the nearest uP ground pin to the crystal pins. On the other side of the PCB, connect the uP ground pin to the plane. This approach works well, both in keeping emi radiation down and keep other currents out of the crystal. Your cap values should be a few pf less than twice the load cap spec of the crystal.
Electron <spam_OUTelectron2k4TakeThisOuT
infinito.it> wrote:
{Quote hidden}>
>Hi!
>Should I return the ground of the caps of a xtal to the nearest Vss pin
>of the MPU, or returning them to the opposite side, where I have a ground
>plane readily available, is exactly the same?
>
>I heard the first would be better.. but will it really make any difference?
>
>Cheers,
>Mario
>
>