working on a new pcb board layout for the intel 82576 processor, I have some questions regarding the crystal layout. Our board layout contains four layers, where the second layer is a ground plane. Is it desirable that the ground plane will continue without any ground-cut under the crystal and their load capacitors? We`re using a through-hole HC49 crystal with 30ppm. Are there any advantages to use a SMD HC49 crystal?
If I`m right, then the return current from the crystal will go to the digital ground of the intel processor. Unfortunately the bga pins around the XTAL pins (N23, N24) are only physical-ground-connections (e.g. N22). Could it be that we will get in troubles if the return current from the crystal will go through these gnd pins?
Do you have any further recommendations regarding the crystal board layout?