Other Parts Discussed in Thread: MSP430F5529
While testing a CDC product with MSP430F5503 we run into problems that the MSP430 USB device randomly disconnects.The frequency varies from few hours to few days. I noticed that the application, which is using the COM port on PC, somehow affect the frequency (some can cause the issue more often).
Symptoms:
Under Win 7, the COM port number simply disappears from Device Manage/ Ports (COM & LPT) section and the application stops receiving new data.
Under Win 10, it usually stays listed and the application, which is using the port, freezes and it is not possible to reconnect to that port. More rarely "Unknow USB Device (Port Reset Failed) (Windows has stopped this device because it has reported problems. (Code 43) A USB port reset request failed.) " appears under Device Manager/Universal Serial Bus controllers.
The app on MSP430 is not frozen, it is not reset and continues to execute while this happens. Oscillator nor MNI fault was detected by MSP430. Only USBCDC_sendDataInBackground starts returning timeout after while. I went through the USB module registers after incident, but nothing "interesting" catch my eye.
The problem is present also with C3_EchoToHost example application from MSP430USBDevelopersPackage_5_20_06_02 package. Tested on custom board with F5503 and on MSP-EXP430F5529 kit. IAR MSP430 6.3 was used to compile the code.
I will be grateful for any ideas or experience.