TS3USB221ERSER Device detection issue.

Hi all,

We are using two TS3USB221ERSER Mux/De mux's in our design, One as input  Host port (Pen drive will attach here) and one more as output for device port(It will connect to PC).

Please see below for my switch use case architecture.



We observed following behaviors.

1) Both mux/De-mux IC's are powered up and sel pin of IC1, IC2 are Zero(0V): In this condition , we should able to access direct pen drive  in on device connector to attached PC.
    
Actual: We saw that "unknown device detected" message in PC.It is not detecting the pen drive content.I removed the pen drive and connected mouse.Mouse was working properly. I am able to see mouse movements also.

2) Both mux/de-mux IC's are powered up and sel pin of IC1,IC2  are high(3.3V):In normal mode(here processor will interact), we are able to do detect the pen drive from host port through USB 1 Interface of the processor.But not able to access the pen drive content on device port to attached PC."Unknown device detected " message getting in device manger.I am getting the USB0 signals waveforms on IC2 mux/de-mux output also.


We tried below things:
1) We changed the Device port connector Type-A to TYPE-B/mini USB.This time successfully accessing the pen drive in PC both the sel modes(high and zero). USB TYPE-B connector is used as input in TS3USB221/A/E EVM also.What is the reason for this?
2) We have bypassed the IC2(mux) and connected USB0 signals are directly to USB TYPE-A connector. We are successfully accessing the pen drive.


In both the cases, it is working.But, We are not understanding , Why USB Mux/De-mux TS3USB221ERSER is expecting for USB Device connector Type-B or mini USB to access the USB device.

It would be great, if anyone can provide the quick help on this.

Thanks,

Regards
Swapna.B