TM4C1294NCPDT: What is the best way to test USB cable removal?

David Chance

Part Number: TM4C1294NCPDT

Using usb_dev_bulk example, after connected to PC via USB, What is the best way to test USB cable removal? (I can test the absent of SOFs timeout, but I don't think it is the best approach)

Thanks for pointer!

over 7 years ago

0 Charles Tsai over 7 years ago

TI__Guru**** 191906 points

Not clear with your question. Are you asking from s/w perspective or h/w perspective how to detect the removal of the usb cable?

0 David Chance over 7 years ago in reply to Charles Tsai

Genius 4775 points

Sorry, I meant software detection

0 Ralph Jacobi over 7 years ago

TI__Guru*** 135355 points

Hello David,

If you are a device and the cable is disconnected, couldn't you just monitor that VBUS is absent and use that as a basis for the cable must be disconnected?

0 David Chance over 7 years ago in reply to Ralph Jacobi

Genius 4775 points

Since I don't use any power from USB and I need control the function of USB port, VBUS is not even in the design...

0 Ralph Jacobi over 7 years ago in reply to David Chance

TI__Guru*** 135355 points

Hello David,

It looks like TivaWare doesn't really have a solution for that case. Disconnection should be triggered from the host and that is how the usblib was put together. I don't see any API's to check for a disconnection on the device end. From my searching there seem to be cases of some systems implementing such checks but it's nothing we have done with TivaWare as that concern had no come up before.

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TM4C1294NCPDT: What is the best way to test USB cable removal?