USB output drivers or power clashing?

Do you ever have to worry about driving power both ways into Beagle
through the USB and from the power jack? For instance if you use a
USB mini-A to A to connect to a host PC, the board does take power
from the USB. Does this mean you should avoid providing power through
the power jack at the same time?

Also related, do you ever have to worry about the output drivers
clashing (both ports in host mode) ?

I'm not a USB expert as you can probably tell...

Thanks.

Ian R <ian.rickards@btinternet.com> writes:

Do you ever have to worry about driving power both ways into Beagle
through the USB and from the power jack? For instance if you use a
USB mini-A to A to connect to a host PC, the board does take power
from the USB. Does this mean you should avoid providing power through
the power jack at the same time?

No, connecting both is fine. There seems to be a switch in the power
jack.

Also related, do you ever have to worry about the output drivers
clashing (both ports in host mode) ?

I would hope the USB interface specification requires tolerance
against this, but I don't know for sure. Perhaps somebody else does.

When a DC plug is connected to the Beagle, the USB power is disconnected. There is no conflict.

There is only one USB port on Beagle and hence only one driver on the board, so there is no clashing to worry about. The port operates as either a host or peripheral depending on what mode it is operating in as set up by the SW.

Refer to the HW Refernce Manual for more details http://beagleboard.org/hardware

Gerald