Note that this series is now under EOL and is not recommended for new designs.
The FT51A Toolchain is a free tool to enable code development and debug for the FT51A series and are based on plug-ins for the free popular IDE using the SDCC compiler. Driver support for each of the main functional units of the MCUs are also included in the installation package, provided as C code and precompiled binaries in addition to sample projects.
Click here to download and install the FT51A Toolchain.
Refer to AN 352 FT51A Toolchain Installation Guide for more information.