Hi all,

We have made a proto type board based on the AT91SAM9G20EK. We are facing issues while doing USB transaction to board (Board as USB device) from PC.

When using Sam-ba to program our board we can see errors in USB transactions. We analyzed the USB transactions using USB analyzer. The error observed was, ack missing for bulk out transaction and Samba becomes non responsive. But when using samba with the development kit AT91SAM9G20EK the USB communications are proper.

The SDRAM, USB device and associated circuitry are same for our board and the development kit's board. Can you please give idea on the possible errors? Do we need to look into more details while AT91SAM9G20 and its USB device circuitry while designing board?

Regards,
Bijesh V.M.

What crystal frequency are you using? I've got the same problem on a custom AT91SAM9263 board with 18.432 MHz (not standard 16.36766 MHz crystal).

My custom sam-ba extram applet detects and configures the SDRAM correctly. The custom dataflash applet however only works about 50% of the time, with the USB losing sync halfway through a dataflash erase. I'm starting to suspect my PLLB RC values.