Re: [Xylo-SDR] RFC - Motherboard

[Philip Covington <p.covington@gmail.com>]

On 1/24/06, Leon Heller <leon.heller@bulldoghome.com> wrote:

> PCI isn't relevant, it uses very tricky stuff involving reflections on the
> bus. This means that the the lengths of track from the interface to the
> connector have to be the correct length. PLX who make generic PCI interfaces
> probably have details on board design on their web site.
>
>
>
> If the bus is terminated properly, as I said the other day, it should be OK
> for our purposes.

A method that I have used in the past with success is to make the
motherboard 4 layers.  The top layer is a ground plane, the bottom
layer is the +5V plane, and the middle two layers are used for bus
trace routing.  If the +5V plane is bypassed properly it is basically
at ground potential as far as RF is concerned.  The top and bottom
layers then act as a shield with the signals sandwiched in between.

Phil C