Hi Kevin,

What are the sdd files for and why would they be different?

SDD files contains some kind of radio calibration data and Bluetooth
arbitrage tables.
They must be aligned with particular RF design and presence of Bluetooth PTA.
If you are using PTA is your design, you should have SDD with PTA tables in.

I noticed the driver parses some information directly from the sdd
file in the cw1200_parse_SDD_file function.  Does the file get used
for anything else?

It is downloaded to firmware and the firmware uses data from it.

If a PTA element is found the code always sets priv->is_BT_Present =
true.  If I do not have Blue Tooth in my system should this still be
set?

Yes if you share antenna and use PTA (Bluetooth arbitrage) in your design.
But in this case you should have SDD with PTA entry in.

Dmitry