Warning (14320): Synthesized away node - FFT IP core

Dear All,

I hope you are doing well.

I am currently working on creating a custom IP core to integrate with NIOSII.

The custom IP encompasses configurations for both the wm8731 and FFT. I am now in the process of adding a register map for the FFT signals to the audio wrapper.

The project is structured as follows:

• Custom Verilog audio modules (i2c controller, codec wm controller, fifo buffers) for handling audio.
• A top module to interconnect all these modules.
• A wrapper to facilitate the creation of the register map.
• Programming in C.

I have tested the current setup, and it is functional.

Now, I am attempting to incorporate the FFT IP into my project. For the FFT IP, I have developed:

• Verilog modules for memory and FFT.
• A memory controller that receives data from the audio and with control signals, passes the ADC data to the FFT module.
• Dual-port RAM in both the memory and FFT modules.
• Initialization in the top module alongside other audio modules with no warnings.

However, when attempting to add as wire the fft signals to the wrapper module in order to create the register map, I encounter 1300 warnings, specifically

Warning (14320): Synthesized away node "top:codec_unit|MemoryModule:MemoryModule_inst|ramaudio:audiosamples|altsyncram:altsyncram_component|altsyncram_8ij1:auto_generated|q_b[21]".

I would appreciate your insights on this warnings and how I can resolve them.

Also whether my approach is considered good practice and if it is possible to create a custom IP core with nested IP cores, such as the FFT IP ?

Please note that I don't have a license for the FFT IP, but I have read that it can be used in evaluation mode for 1 hour.

As a postgraduate student working on my thesis, I hope I have clearly articulated my question. Your advice would be highly valuable.

DE2-115 board.

Quartus prime lite 20.1.

Thank you.