I just received the DEMOFLEXISJMSD board. Using USB Prober on OSX, I wanted to see the descriptors, but the device did not enumerate on the USB. My hunch was that perhaps the firmware did not allow the USB to initialize unless an SD card was physically inserted, so I purchased a 2 GB SD card and tried again. This time, the device will enumerate and I can see the descriptors. However, after a brief pause (less than 1 minute), the device will disconnect from USB.
Before I break out the USB Protocol Analyzer, I'd like to know whether the default firmware is a fully USB compliant implementation. Can anyone give a definitive answer? Any details would be appreciated.
I searched the discussions here, and found complaints about the maximum SD bandwidth, but that's a separate issue from maintaining the USB connection.
I tried again under Windows, and a Card Reader appeared, but I could not access the contents of the SD.
I had a USB analyzer attached, and it shows some transfer errors at about the time the Mac would have disconnected. It seems that these might be related. I don't know whether the SD was accessible because it's unformatted, or because of the USB errors.