about multi-virtual CDC port

[lpcware]

Content originally posted in LPCWare by iamonline on Sat Apr 19 04:59:21 MST 2014
Hi:
    I want to create 4 virtual com port through USB on LPC1768 chipset. I have rewrite Configuration Descriptor and some EP_IN/OUT function but my PC only can only enum 2 virtual COM port. Can anybody tell me why PC only enum 2 virtual COM port? My system is WIN7 x64. The attach is the picture of enum result.
  thanks.

[lpcware]

Content originally posted in LPCWare by robert hulsebos on Fri Dec 11 09:25:29 MST 2015
Hi there,
I am interested in a multi virtual COM port through USB on our LPC1769. And I hate re-inventing the wheel. Is there any way you could help me by sending source code or explaining what needs to be done to the LPCopen example code of CDC/Composite driver?

Regards,

Robert

[lpcware]

Content originally posted in LPCWare by iamonline on Sat Apr 19 08:28:17 MST 2014
Thank you for your reply.
I re-check the descriptor, but I cannot find any mistake. Another strange thing, I write 3 Virtual COM in descriptor, PC can enum 2 virtual COM, while if I write 4 virtual COM in descriptor, PC can enum 3 virtual COM. Attach is the pic which I write 4-IAD in the descriptor, but PC only show 3 Virtual COM. Why? Can you give me some advice?
Thanks a lot.

[lpcware]

Content originally posted in LPCWare by capiman on Sat Apr 19 05:23:24 MST 2014
Hi,
I assume some length in (config) descriptor are wrong.
Perhaps post the file containing the descriptors.
Have you tried usbview, I think it is checking at least some of the length for validness.
Best regards,
Martin