Yes, Anchor download can be achieved with CyAPI.lib/CyUSB.dll and CyUSB.sys. Anchor download is nothing but A0 vendor command. This vendor command is used to download firmware to EZ-USB (AN21xx/FX/FX1/FX2/FX2LP). Please refer to the CCyControlEndPoint section 5 of the CyAPI Programmer’s Reference guide or section 4.3 of CyUSB .NET DLL Programmer's Reference available as part of SuiteUSB 3.4.5 for details on how to send control transfers. Using this you can send your desired control transfer including anchor download.