How to convert floating point code to fixed point? I am working on converting a floating point MATLAB code into fixed point C code. The code is to be run on a DSP platform, the specifics of which are yet to be decided. 

I'm new to floating point to fixed point conversion and am facing quite a few challenges.

My questions are:


What is the best way for me to start and where should I start, because the topic is quite confusing.
My MATLAB code is basic filtering code; there's FFT, windowing followed by IFFT. Windowing seems simple enough as its multiplication, but I'm totally lost when it comes to FFT and IFFT.


Thanks!
Having a standard fixed point library available as a reference implementation would be helpful 

There are more than a few fixed point dsp libraries, some with source code and documentation. Google returns many links. 

TI and Analog Devices have fixed point libraries that support their products. The documentation and support is very helpful. 

Matlab also offers fixed point add ons. Student pricing is very affordable.