[hpsdr] Cypress USB Problem

[Sami Aintila]

On 7/5/06, Christopher T. Day <CTDay at lbl.gov> wrote:
> There is one more boot condition that I'd forgotten. If there is an
> EEPROM, and it does not start with either 'C0' or 'C2' _and_ pin 35 on
> the 128-pin version of the FX2 (this is the EA line) is held high, then
> the FX2 will try to boot from an external RAM, which doesn't exist on
> Ozy. That chip will supply, among other things, the VID and PID.
>
> Now, since you've tried to boot both with and without the EEPROM, this
> doesn't seem likely, but maybe you should poke just a little more around
> pin 35; it's floating in the schematic.
>

But a blank EEPROM (if it hasn't been pre-programmed) will contain all
'FF' data, so if EA is high (or worse, floating) there will be
problems. In any case EA should be low if you're not using off-chip
memory. And in general, no input should ever be left floating. I'm
unfamiliar with the OZY, but it seems also pin 101 (WAKEUP) is
floating.

73, Sami OH2BFO

 1152081741.0