?USB Host port removal from B.4 board availabe from DigiKey?

Hi, There,

Per “Beagle Rev B4 Hardware Reference Manual” dated July 11, 2008 for the board available from Digikey, there are the statements:

“USB host port was removed due to operational issues.”

“The USB Host has been removed due to issues with the PCB layout. While working, the USB Host port was not reliable.”

Anyone can please specify a little bit more on this operational issues, it is hardware issue or software issue? or just purely due to PCB layout issue and firmware/software is fine?

Does the Rev A board has the same problem?

I can not find any Rev A documentation on beagleboard.org, anyone can point me some useful link?

Thank you

chuqdd

It was a PCB layout issue. http://code.google.com/p/beagleboard/wiki/USBHostTestREPRODUCE
was used to verify the issue. It was primarily a power supply noise
issue and we don't expect to have boards that resolve the issue until
November/December. Rev A documentation is still linked from
BeagleBoard.org - resources.

The same design is found on the REV A and REV B boards. In addtion ot
the layout changes, the supply rail to the PHY is being changed from
the VBAT rail to the main 5V rail to help withthe noise.

Gerald

Gerald,

"In addtion ot the layout changes, the supply rail to the PHY is being
changed from
the VBAT rail to the main 5V rail to help withthe noise" will happen
on the new revision other than rev A/B?

When is the new revision expected?

Thank you

Don

That is on REV C slated for the November time frame.

Gerald

Dong Chu wrote:

Hi, There,
Per "Beagle Rev B4 Hardware Reference Manual" dated July 11, 2008 for the board available from Digikey, there are the statements:
     "USB host port was removed due to operational issues."
     "The USB Host has been removed due to issues with the PCB layout. While working, the USB Host port was not reliable."
Anyone can please specify a little bit more on this operational issues, it is hardware issue or software issue? or just purely due to PCB layout issue and firmware/software is fine?

http://elinux.org/index.php?title=BeagleBoard&diff=6627&oldid=6625#Errata

#5

Does the Rev A board has the same problem?

http://elinux.org/index.php?title=BeagleBoard&diff=6627&oldid=6625#Availability

I can not find any Rev A documentation on beagleboard.org, anyone can point me some useful link?

http://beagleboard.org/resources

-> Rev A5 Hardware Technical Reference Manual

I read the A5 manual, it states that:

"Beagle USB Host only supports HS USB (480Mbps/S). Low Speed and Full
Speed devices are not supported unless they are connected through a
USB Hub prior to connection to the Beagle. The OTG port does support
LS and FS devices"

My question:

This limitation of A5 version is due to the PHY used (SMSC USB3319/
USB3322?, confused by the schematics having 3319 while the paragrah
following it says 3322) or due to OMAP USB port1 used?

I am interested in A5 version because I plan to use the USB host port.
While only B4 is publicly available at this moment, is there any way
to get some A5 boards?

Thanks

The port on the A5 board is NOT fully functional and was removed on the B4 version. The issue is that it will lock up under heavy loads due to a layout issue that was causing the PHY to lock. The USB3326 is the device used and is the only device ever used.

The port on the OMAP device will only support HS devices. This is an OMAP limitation and not a PHY limitation. To use low speed devices on this port, an external hub is required.

There is no way to get A5 boards, and as I have said, it is NOT functional.

Gerald

The port on the OMAP device will only support HS devices. This is an OMAP
limitation and not a PHY limitation. To use low speed devices on this port,
an external hub is required.

Is this because Port0 (OTG port) has already been configured as HS,
which forces all other USB ports in HS mode? If OTG port is configured
in FS/LS, still Host Port can handle FS/LS without a hub. If this is
the case and I want only FS/LS, which part of firmware/software does
you think I need to study?

Thanks

The Host port is ONLY HS. That is all that it will support. It cannot do LS/FS because it was not designed to support this mode. This is a HW limitation and has nothing to do with SW. It is totally independent of the OTG port on the Beagle. They are not interrelated.

The port can be configured to a 4wire or 6 wire mode to support LS/FS, but then it cannot do HS. On Beagle it is a ULPI interface supporting HS only. I suggest you refer to the OMAP3530 TRM for more information on the inter workings of this interface.

The OTG port on Beagle can support FS/LS/HS in the Host or Client mode.

Gerald