As with all Silicon Labs products, the CP21xx portfolio is supported with outstanding technical documentation to help developers answer the occasional difficult question. Whether looking for implementation guidelines, hardware user’s guides or for a better understanding of APIs themselves, everything the user needs to develop is included on Silicon Labs’ website. To request that Silicon Labs pre-program a custom VID/PID number and/or serialize devices prior to shipment of CP21xx USB devices, contact a Silicon Labs sales office or authorized representative.