Re: [OpenOCD-user] FT2232 device

[Trampas S. <tr...@gm...>]

I have it all working now...

I was a bit confused on the SWD, and how to connect TDO/TDI with TMS
signal. However after reading about SWD I realized the SWDIO is
bidirectional bus and the adapter should have an open collector driver to
pull down, where I was doing a push/pull. The resistor hack is basically a
hack, but would be better if a Schottky diode was used with a pull up
resistor. This would simulate the TDI being an open collector driver and
only pulling down the SWDIO.  Also for some hardware the debugger should
have a pull up on the SWDIO.

Thanks to everyone for their help!

I will be updating my schematics and open sourcing the hardware design. The
current design supports JTAG and SWD for 3.3V I am also working on an
isolated version that will support JTAG and SWD for 0.9V to 3.3V.

I would like to include an INF file for automatically installing the WinUSB
driver, if someone has examples of how to do this I would love to get the
information.

Thanks again
Trampas

On Mon, Aug 1, 2016 at 7:48 PM, Trampas Stern <tr...@gm...> wrote:

> Yea, I will build up another board and test it...
>
> Here is the logic analyzer of the signals...
>
> [image: Inline image 1]
>
> On Mon, Aug 1, 2016 at 7:31 PM, Juan Cecconi <jce...@nu...>
> wrote:
>
>> Yes, it now appears like a HW problem or swd config problem, but not an
>> openocd or FTDI issue.
>>
>>
>>
>> El 1 de agosto de 2016 5:37:19 PM GMT-03:00, Trampas Stern <
>> tr...@gm...> escribió:
>>
>>> The libusb issue is resolved. Issue was I defined descriptor in config
>>> file that did not match the driver.
>>>
>>> The adapter I have uses tristate drivers to switch the signals for SWD.
>>> I moved adapter to a JTAG board and it is not working there either. I am
>>> debugging hardware now...
>>>
>>> I have checked pin out but have not found an issue, I will scope the
>>> signals next...
>>>
>>> On Aug 1, 2016 4:10 PM, "Paul Fertser" <fer...@gm...> wrote:
>>>
>>>> On Mon, Aug 01, 2016 at 02:02:59PM -0400, Trampas Stern wrote:
>>>> > Debug: 260 2219 ftdi.c:1092 ftdi_swd_switch_seq(): JTAG-to-SWD
>>>> > Debug: 261 2225 ftdi.c:946 ftdi_swd_run_queue(): Executing 2 queued
>>>> transactions
>>>> > Debug: 262 2235 ftdi.c:978 ftdi_swd_run_queue(): JUNK DP read reg 0 =
>>>> ffffffff
>>>>
>>>> This looks like hardware issue, SWD just doesn't work properly for
>>>> you, the target doesn't respond at all. How is your debug adapter
>>>> supposed to handle SWD specifics?
>>>>
>>>> Regarding your libusb issues, can you please clarify what OS version
>>>> you're using, whether or not you succeeded to get the cited output
>>>> with WinUSB just for a single interface and regular FTDI VCOM driver
>>>> for the other, and can you please show the exact modification that
>>>> made it work in diff -u form?
>>>>
>>>> --
>>>> Be free, use free (http://www.gnu.org/philosophy/free-sw.html)
>>>> software!
>>>> mailto:fer...@gm...
>>>>
>>> ------------------------------
>>>
>>> ------------------------------
>>>
>>> OpenOCD-user mailing list
>>> Ope...@li...
>>> https://lists.sourceforge.net/lists/listinfo/openocd-user
>>>
>>>
>