Now I am working on LPC2468. I need to implement a USB CDC device. I changed the sample code from Keil for LPC2368. The sample code transfers data between UART and USB. For I don't need the UART, I remove the code for serial port. But I don't know how to set the serial state, which is set by CDC_GetSerialState(). This function is called by EndPoint1. Firstly I just delete these code in EndPoint1. The result is there is only first char sent to host. Then there is no any response. Please give me some suggestion. Thanks!