Digital Down-conversion Chain: Converting from Intrinsics to API Introduction Upgrading Tools, Device Speed Grade, and Makefile Upgrading the Code Converting Kernel Functions to Kernel Classes Migrating from Windows to Buffers Replacing Intrinsics with APIs Relocating Global Variables to Kernel Class Data Members Handling State Variables to Enable x86sim Updating Older Pragmas Supporting x86 Compilation and Simulation Building and Running the Design Setup and Initialization x86 Functional Simulation Hardware Simulation Summary Support License