I recently implemented a fuzzy logic controller for an elevator using 8052.

I chose to use a Takagi Sugeno model because it was simple to program and didn't take much time.

To make the membership functions you have two choices:
a) you can calculate the value that the function takes using math
routines.
b) you can make a table of the function values in code memory and access them via movc. I chose this one.

Instead of using numbers from 0 to 1 I used from 0 to 100 which resolved the fixed point problem.

Zero order takagi models are the easiest to implement. The math involved is quite simple if you go with option b). Other methods require many multiplications and stuff which usually take too long.
I found the Matlab Fuzzy Logic Tutorial and toolbox to be quite interesting; I also have a 40 page tutorial which might be helpful. Be warned however that it has quite a lot set theory math.