USB-debug // FTDI FT2232D -- need more specs for particular hw design

Joerg Reisenweber joerg at
Tue Apr 29 12:17:06 CEST 2008

Hi Andy,

Andy Green schrieb:
> |> Power isn't the only consideration, we already thought about bringing
> |> out debug USB connector to the outside world.  If that is what we do,
> |> then it is sitting there ready to eat power the same as the OTG
> |> connector, and it makes sense to allow it.
> OK, that's an issue alright :-/  We could make it mini USB for debug I
> guess.  But then we can't share one Power adapter between the two ports.
> ~ So it stops making sense.

Some Q and Remarks regarding "moving debug-board" --
Q- Talking about power to debug-USB: should we power the FTDIchip and
his team by debugcon-Vusb only (using U3, or something less
sophisticated), so it doesn't take any power while no connection to
USBdbg? Are we sure FTDIchip will show the behaviour we need regarding
GPIO-Z|gentle-pulldown etc, while powered down? Or do we need to
maintain power to debug circuitry all the time, to have the states we need.
R- great: the connectors' pin numbers don't correspond on GTA02 &
debugboard. Probably that's the way it is, but... :-S
O- are there any additional Reset issues to take care of? Like reset of
MSP430, reset of the FTDI itself etc...
O- could you have a look at the circuit diagram of debug board and maybe
just prepare a list of parts that are going to vanish? Maybe, even
better, provide a proposal c-diag, that includes detail regarding the
serial communication with MSP430? You told there's something you'll come
up with...
R- the chip needs quite some real estate (LQFP-48) :-(. Allen will groan
about it.
O- maybe we should keep led2? Or even move it to pin6 3V3OUT.
O- do we need U3 TPS2149IDGN anyway for FTDI_5V, or may we take 3.3V for
IO power (14, 31, 17(!??), (10,26 +5V), R67-69) from any other source (PMU)?


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