libftdi Archives

Subject: Re: ftdi_set_bitmode question

From: Joachim Schambach <jschamba@xxxxxxxxxxxxxxxxxx>
To: libftdi@xxxxxxxxxxxxxxxxxxxxxxx
Date: Wed, 03 Aug 2011 12:08:05 -0500

On 8/3/2011 1:39 AM, Xiaofan Chen wrote:
> On Wed, Aug 3, 2011 at 11:17 AM, Michael Plante
> <michael.plante@xxxxxxxxx> wrote:
>> Joachim Schambach wrote:
>>>> I am not totally sure how to interpret usbmon output, but it looks like all
>>>> packets that I am requesting are actually going out.
>> I am not either.  I just know that's an intermediate troubleshooting step.
>> There are several people on the libusb list who can help interpret it.  I
>> recommend writing there if no one gets back to you in a few days here.
> Good suggestion. Alan Stern, for one, will help to decode the
> usbmon log pretty fast.
>
> On the other hand, the usbmon does not seem to tell much if I try to
> follow the usbmon.txt to parse the log.
> http://www.mjmwired.net/kernel/Documentation/usb/usbmon.txt
>
> So maybe the problem is on the FPGA side.

Although nothing can ever be totally ruled out, this one seems highly unlikely
to me. I am using the simplest possible trigger in signaltap to look at the
output from the FTDI chip, namely the RXH# going low, which should indicate that
something has been sent to the FTDI chip. So at that point, no action from the
FPGA at all is involved, since this pin is driven by the FTDI chip itself.....

Jo

>
> f62a4140 770501648 S Co:007:00 s 40 00 0000 0000 0000 0
> f62a4140 770501720 C Co:007:00 0 0
> http://lxr.linux.no/#linux+v3.0/drivers/usb/serial/ftdi_sio.h
> Vendor specific request, FTDI_SIO_RESET, Reset
> Status ok
>
> f62a4140 770502123 S Co:007:00 s 40 03 4138 0001 0000 0
> f62a4140 770502217 C Co:007:00 0 0
> Vendor specific request, FTDI_SIO_SET_BAUDRATE
> Status ok
>
> f62a4140 770502454 S Ci:007:00 s c0 90 0000 0043 0002 2 <
> f62a4140 770502592 C Ci:007:00 0 2 = 0000
> f62a4140 770502603 S Ci:007:00 s c0 90 0000 0044 0002 2 <
> f62a4140 770502717 C Ci:007:00 0 2 = 0000
> Vendor specific request, FTDI_E2ROM_READ
> (ftdi_read_chipid).
> Status ok
>
> d89e87c0 841791213 S Bo:007:02 -115 100 = 00010203 04050607 08090a0b 0c0d0e0f
> 10111213 14151617 18191a1b 1c1d1e1f
>
> Bulk Out transfer submission, device 7, EP 2 Out, 100 bytes of data,
> only partially (up to 32bytes, from 0x00 to 0x1f) displayed.
>
> d89e87c0 841792086 C Bo:007:02 0 100 >
> Bulk Out transfer completion, device 7, EP 2 Out, 100 bytes of data,
> status ok (means bulk out transfer is successful).
>
> d89e87c0 841793348 S Co:007:00 s 01 0b 0000 0000 0000 0
> d89e87c0 841794086 C Co:007:00 0 0
>
> This is a standard set_interface request (select interface 0)
> when the device is closed.
>

-- 
Dr Joachim Schambach                 tel: x1 512 471 1303
The University of Texas at Austin    fax: x1 814 295 5111    
Department of Physics                email: jschamba@xxxxxxxxxxxxxxxxxx
1 University Station C1600
Austin, Texas 78712-0264, USA


--
libftdi - see http://www.intra2net.com/en/developer/libftdi for details.
To unsubscribe send a mail to libftdi+unsubscribe@xxxxxxxxxxxxxxxxxxxxxxx   

Current Thread