AnsweredAssumed Answered


Question asked by Deepak Madan on Jun 10, 2017
Latest reply on Jun 14, 2017 by Deepak Madan

I am trying to connect a USB CDC ACM Device to my LPC2468 using Host on LPC. I am not able to get pass the CDC Stage for the Device.


The Device is USB2.0 Compliant and is using CDC ACM 1.1 with Class Specific interface.. and Bulk In , Bulk Out, Interrupt  Endpoint Descriptors.


My Host Controller detects the Device.

I Set the Configuration also after parsing all the Configuration Descriptors.

I have successfully sent CDC Set Control Line Request (Value: 0x00).

But while trying to Send CDC Set Line Encoding Request (my request fails).

Neither I am able to receive any data for CDC Get Line Encoding Request.


I also tried to read and send Data from Data Bulk In and Bulk Out Endpoints respectively. But I don't get any response or any data. Am i missing something?? 


Below are the Commands which were processed successfully sent in the same Order:


Get Device Descriptor
Set Address 1
Get Device Descriptor
Get Configuration Descriptor (Length - 8)
Get Configuration Descriptor (Length - 0x4B)
Set Configuration - 2 (2:: as Configuration Descriptor Mentioned Configuration Value - 2)

CDC Set Control Line Request (Value : 0x00, Interface : 0x00) (Class Type Request - Recipient Interface - Control Transfer)


The Following Command fails.

CDC Set Line Encoding ( Value: 0x00, Interface: 0x00, Length: 0x07 ) (Data:: Baud Rate: 115200, charFormat: 0, Parity : 0, DataBits: 8)
(Class Type Request - Recipient Interface - Control Transfer) ----


For Above Control Transfer: Setup Stage is Sent Successfully, But Data Out Stage is not Sent Successfully).