I use the MSP430F5632 chip as MCU. When device firstly connect with PC via USB port, the enumeration process may be failed in 10% ~ 20 % device. But it is not totally failed, the device can get the name defined, also the properties of device is correct ( hardware ID, Manufacturer name...). In this case, there is a warning icon beside the device under device manager. Re-plug in the USB cable, the second enumeration process can pass.
We use USB Analyzer capture the data during the fail enumeration as first figure, you can see that in the 13th transfer, PC get "STALL" PID. But the 14th transfer, host PC SET CONFIGURATION again, device response normally. In the end, the device will suspend. (the correct enumeration process should like second figure).
When this case will happened, and how I can avoid this phenomenon ? The USB eye-diagram has been test and pass. The hardware scheme is basically same as user manual.
Furthermore, the USB communication may be halt during the data transmission after enumeration. sometimes the device has been lost, sometimes there is a same warning icon behind the device.
