Monthly Archives: June 2015

exp() calculation for micro processors

You frequently encounter a situation that exponential function is necessary when you work on a musical instrument project using micro processors.  Its generic implementation is slow and space consuming, so is not suitable for micro processors.  So I need to do some alternative implementations.  For those implementations, space and speed is important but accuracy may be sacrificed 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.指 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.