pls,go to http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/100/p/49226/174600.aspx#174600 for detailed info, thanks! other IT engineer had post some info, but no any valueable suggestion!
HII!
I have a big problem, I use Dm355 as a camera with wifi function. so I select an usb wifi module(ralink RT3070 chip). this usb wifi is working very nice on DM355. but my camera is also connected with PC by USB cable,
Because this usb wifi must be in the body,and DM355 has only one USB controller, so I have to use a high speed usb switch to switch usb D+,D- .
when the camera is working at usb cable mode(connected with PC), usb wifi is powered off, a fig can show this.
1: DM355 as a slave device, PC as a host, everything is good, whatever which usb switch is used.
2:if DM355 as a host, it cann't communicte with usb wifi module(usb switch is on the bus)
3:but if usb switch is removed, Dm355 can communicate with usb wifi module,
This usb switch is also TI product, TS3USB30E.
It seems that the Ron resistance of usb switch disturb the usb line, and the DM355 cannot drive the usb wifi module.
Can any body give me some advice?
Thanks!
Hi,can anybody give me some advice?
Hi David,
I noticed you placed a common mode choke (L14) on on your differential lines. Have you retested the performance with this component bypassed or shorted?
The bandwidth of our TS3USB30 switch is 900MHz which gives plenty of margin for HS USB2.0 signals (240 MHz) but we do have other switches with better performance.
I would recommend evaluating the TS3USB221 (1200 MHz) or TS3USB221E (1000 MHz) for comparison.
thanks! I wait this message a long time!
yes. this choke is bypassed, but still fail.
DoesTS3USB30E or TS3USB221a(e) was tested in Dm355 or DM6446 such like platform?
I have no TS3USB221 sample and can I apply demo board form local support?
David,
These switches were eye pattern tested using the standard USB compliance test fixture, electrical test software, and Tektronix scope with USB compliance test package installed. They passed the full set of eye pattern tests without any issues.
We do in fact have EVMs available for TS3USB221x devices.
http://focus.ti.com/docs/toolsw/folders/print/ts3usb221evm.html
http://focus.ti.com/docs/toolsw/folders/print/ts3usb221aevm.html
http://focus.ti.com/docs/toolsw/folders/print/ts3usb221eevm.html
-Jason