Hi erich, thank for the answer, mi problem is that i need transfer data using usb, i working with the 52211, so i thought to switch to kinetis cos it have examples and components like usb_ldd and mqx_lite, but now i find out that there are some examples for 51 processor to use usb interfaz, now i ask you, where can i download examples using usb_audio, or usb_medical_data_transfer for the 52211 and components for processor expert, thank you so much