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LPC1837 And USB1 FS Device Enumeration.

Question asked by workalot on Sep 27, 2017
Latest reply on Oct 9, 2017 by Carlos_Mendoza

Workalot is stuck getting a CDC VCP up and running. At this point I get to the where an address is set, but when Windows asks for the configuration descriptor (67 bytes) the first 64 bytes arrives and not the remaining 3 bytes.

 

So, my understanding of DQHs and DTDs needs edification.

 

Does a one setup of DTD cover all 67 bytes or are two setups required?

 

At UM10430 Rev 3.0, sec 23.10.11.2, page 611 the instruction "3. Fill in total bytes with transfer size." Would this be 67? Or 64?

 

I have tried both ways but only 64 bytes gets the the PC (as per MMA log). 

 

I should add that I eschew demo libraries and favour roll your own.

 

Thanking in advance,

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