Hi,
I have a custom board with the TPS65981 part with block diagram shown below. There are zero ohm resistors that can be populated to support either USB Type-C path or USB 2.0 path. When I connect the USB Type-C path and connect the USB cable, I see in the host PC device manager a new COM port show up and then it disappears a couple of seconds later and becomes a separate device labeled TPS65981 in device manager. TPS65981 pins 4 and 5 are connected to the USB HUB. TPS65981 pins 6, 7, 8 and 9 are connected to the Type-C connector.
When I connect the USB 2.0 path and connect the USB cable, I see in the host PC device manager a new COM port show up but then it stays enumerated. I have connected the output of the USB to UART IC in loopback (short RX and TX) and can see the loopback in a terminal on the host PC.
It appears there is a configuration problem I have in the TPS65981 that is causing the COM port to enumerate and then go away and instead be recognized in the device manager as TPS65981. What settings in the TPS65981 might cause this sort of behavior? I am using application customization tool version 6.1.1.
Thank you.
