A data file is an array of integer or std_logic_vector with a .txt or .dat file extension located in the same directory as the config file and application module files. Some API calls such as the WRITE_FIFO_DATA and the SHARED_REGISTER procedures provide overloads for the std_logic_vector_array and integer_array type inputs and SpeakHDL provides helper functions to read an array from a file. When defined properly, many synthesis tools such as Xilinx Vivado allow constant data arrays created from data files to be synthesized.