Hi,

I would like to know if I am the only one having problems to get SAM-BA working with OHCI-based USB controllers (mostly found in AMD-based motherboards). As suggested by Atmel, I'm using usbser.sys driver to program my AT91SAM7SE512 microcontroller under Windows 7 (both 64-bit and 32-bit versions).

I'm using a simple terminal program (Tera Term, Bray Terminal or whatever you prefer) to communicate with my microcontroller in bootloader mode. In order to keep the test as simple as possible, I'm trying to send only a simple 'ping' command:

T# (switch to interactive mode).

I can only see the correct reply (the prompt character '>') under Intel-based (that use UHCI-compatible USB controller) PCs but I can't get any reply form PCs that use OHCI-based USB controller.
I also tried to use a USB sniffer, so I am sure that the command is sent properly to the microcontroller. The problem is that I cannot see any response ('>') as expected.

It seems to me that the problem could be related to a timing issue, because using an alternative driver, found here
http://www.recursion.jp/avrcdc/driver.html#windows
the USB communication with SAM-BA works properly (but very slowly).

Is there anyone that know if a workaround exist for this issue (without using the driver above, because Atmel say that SAM-BA should work properly using 'usbser.sys' under Windows Vista/7)?

Please note that my tests are done with the latest versions available of usbser.sys for Windows 7 and Windows 7 SP1 (6.1.7600.16385 and 6.1.7601.17514), for 64-bit version.

Regards,
fcarlo

I can confirm that this problem also apply for Microsoft Windows XP 32/64 (with latest Service Packs) as well.

I suspect that the problem could have something to do with the information found here:



http://www.lvr.com/usbfaq.htm

"Why does my device work with UHCI hosts but not OHCI hosts?

OHCI hosts may do multiple stages of a control transfer in a single frame, while UCHI hosts do each stage in a different frame. Every USB device should function under both host types."



Unfortunately, I have no official response from Atmel's FAEs :(