IMX6. Problem with camera via USB OTG

[spodarets]

Hi!

We use the USB OTG port in IMX6DL to connect video camera in High Speed operation. In the production of a series of devices, some of the devices (about 20%) work with image errors (freezes, noise, etc.). If we connect the camera to the USB Host1 port, there are no problems, the image is normal. The hardware implementation of the ports is almost the same (the difference is only in the trace of the PCB). We were able to solve it by selecting the 45-ohm resistance for the USB_DP and USB_DN output pins through the TXCAL45DP and TXCAL45DN bits. But the problem is that for each device in the series, individual settings in bits are needed. Are there any other port settings to solve this problem? Should there be external hardware differences in the USB OTG and USB HOST1 ports?

[igorpadykov]

Hi Viacheslav 

if tweaking "TXCAL45" helps this may point to layout problems and

one can recheck usb layout guidelines given in

IMX6DQ6SDLHDG, Hardware Development Guide for i.MX 6Quad, 6Dual, 6DualLite, 6Solo Families of Applic...

Best regards
igor
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[spodarets]

Hi Igor,

Thank you for the reply.

Yes, the layout should definitely be checked. But the strange fact is, that in our project the trace for USB HOST1 is made worse, than for USB OTG (since we did not plan to use USB HOST1 in High Speed operation). However USB HOST1 works!