Southernboy,
To allow for a reduced pinout, the 5274 and 5275 families leverage DDR technology to get 32 bits of data on only 16 data pins on the package.
On some of our larger, less pin constrained parts, we offer SDR and DDR. The 548x and 547x offer both.
But to be honest.. I've been using DDR for about 6 years now, and it works quite well with the Coldfire family and I wouldn't go back.
Integrating a DDR solution on the 5274 is relatively straightforward.
I would be happy to help if you need some guidance.
Others on the forum may have similar questions, so if you are thinking of using DDR but have concerns...Then just fire some questions to the forum and we'll try to help.
Best Regards,
-JWW