I often encounter a situation that exponential function is necessary when I work on a musical instrument project using a microcontroller. Its generic implementation is slow, so is not suitable for micro processors. I need to do some alternative implementations. For those implementations, space and speed is important but accuracy can be compromised in many cases.
Follows are articles about fast and compact exp() implementations, for my future reference.
http://www.convict.lu/Jeunes/ultimate_stuff/exp_ln_2.htm
http://www.quinapalus.com/efunc.html
I’m currently using a table lookup approach that I implemented before for an envelope generator I prototyped before. This one is still a little slow and large, but it’s running in PSoC 4200 without major problem anyways. So I’ll keep it for a while.
