Hello,
I am using TM4C1237H6PZ for sending data through USB cable(as a virtual COM port on my laptop) continuously. I kept my machine for testing overnight with data transmitting to hyper terminal. It was working fine until next day when i started disconnecting and connecting the USB cable from my laptop for the purpose of testing. As per my observation, the hyper terminal was able to receive the data after disconnecting and connecting the connection from the hyper terminal when the cable was pulled out and inserted back. But after a few trials, a situation arose when the machine was no longer transmitting data to the hyper terminal. Usually when i disconnect the connection from hyper terminal, i get the event as USBD_CDC_EVENT_SET_CONTROL_LINE_STATE. When i pull out cable i get the event as USB_EVENT_SUSPEND. When i reconnect the session i get the following events:
USBD_CDC_EVENT_GET_LINE_CODING
USBD_CDC_EVENT_GET_LINE_CODING
USBD_CDC_EVENT_GET_LINE_CODING
USBD_CDC_EVENT_GET_LINE_CODING
USBD_CDC_EVENT_SET_LINE_CODING
USBD_CDC_EVENT_GET_LINE_CODING
USBD_CDC_EVENT_SET_CONTROL_LINE_STATE
Then it connects fine.
But in that error situation, when i disconnected from hyper terminal, i got no event. And when i connected again, i got USBD_CDC_EVENT_GET_LINE_CODING event 6 times and then nothing happened and connection did not establish. I then restarted the hyper terminal application as i though hyper terminal is not communicating properly. Still the same issue. I then restarted my device and then it worked properly and connected with proper events. Please suggest some methods to debug this. Is there any buffer overflow or any thing else that may be happening?
Thanks,
Naman