Hello Yang,
Atmega 328p microcontroller has a Program Memory Size of 32 KB and a RAM of just 2 KB.This is fairly less than the memory that is required by the code generated by your model to do its processing.
Data memory that is a volatile memory is used for storing variables, intermediate results, and other runtime data during program execution. Overflow of data memory indicates you might have way too many variables and you can solve it either by optimizing your code or deleting unused variables to clear up space.
You can also think of using a different development board that has bigger memory storage capacity and a better RAM to carry out the processing that you require.
