lpc11u14 API software could not detect com port after re-plug has been created.

[lpcware]

Content originally posted in LPCWare by wilson.lee on Mon Jan 26 06:37:59 MST 2015
Hi, Everyone,

I have a problem of LPC11u14 USB CDC function.

My sscom terminal software could not read lpc11u14 com port after I re-plug usb, but I can see the lpc11u14 com port in device manager.

The testing steps as below:
1. plug in lpc11u14 usb
2. open sscom
3. select lpc11u14 com port, and connection succefully
4. plug out lpc11u14 usb (sscom still open com port)
5. plug in lpc11u14 usb
6. close sscom com port fail, and just close sscome software.
7. open sscom software again, but I could not read any com port from sscome
and there is no com port I could select.

Please help me to solved this issue.
Thank you very much

[lpcware]

Content originally posted in LPCWare by Tsuneo on Mon Jan 26 17:38:29 MST 2015

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Quote:

If lpc11u14 could not do the same way, could you teach me why lpc11u14 could not?

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I believe you are testing on Windows.
As Windows in-box CDC driver, usbser.sys, is defective, you can't get the behavior.

In these topics, I wrote on the details and workaround.
http://e2e.ti.com/support/microcontrollers/tiva_arm/f/908/t/371674
http://e2e.ti.com/support/microcontrollers/tiva_arm/f/908/t/390690

Tsuneo

[lpcware]

Content originally posted in LPCWare by wilson.lee on Mon Jan 26 07:46:58 MST 2015
Hi, R2D2 sir,

it will be okay, if it changed 5 and 6.
but user will confuss when should unplug lpc11u14 usb.

In my mind, lpc11u14 usb should be liked PL2303 or FT232RL.
The API software could detect the devive com port after restart close com port and software.

If lpc11u14 could not do the same way, could you teach me why lpc11u14 could not?

thank you a lots.

[lpcware]

Content originally posted in LPCWare by R2D2 on Mon Jan 26 06:40:32 MST 2015
Then change 5. and 6. ...