I need to find the value of e^(-x/y); where y is the constant and x keepschanging.
Does anyone know how to find this value on Xilinx FPGAs. Is there any core available for it? or any Algorithm would also do.
Thanks in advance.
Like all things, having an idea of what X is: complex/real, fixed/
floating point, range & resolution, bandwith and allowable latency to
get the answer (and what is its kind/range/resolution?) are going to
impact the choice of method to do the calculation.
Also, is Y REALLY a constant, or is it a parameter that changes very
infrequently, but you don't want to have to re-synthesize, place &
route to change it?
Without knowing the above, and since you only have one real-time
input, I would hesitantly suggest a look-up table, and depending on
range/resolution of the input and the result, linear interpolation
between table entries. Depending on the target architecture (whether
block ROMs are available), you may be able to populate the table with
a VHDL initialization function for the constant array that is the
table.
Andy