Thomas:
Unfortunately I get virtually no say on the choice of hardware selection. The customer is committed to PDIUSBD12 for various reasons and I do not know all the reasons. Several criteria they had that I do know of...

* The microcontroller in use must be operating at 3.3 Volts.

* They need FLASH capacity in product of 1 MByte.

* Interface to USB had to be parallel becasue the pinout of the processor has no spares.

Michael Karas