lookup table optimizer claims function has states, but has non

Hi everybody,

I try to use the loopup table optimizer for a function within a simulink block intended for hdl code generation.

the function is:

function T = fcn(input)

A=1.6157254;

B=-1.086193e+05;

C = 1.98e-25;

D=1.38e-23;

T=(C/(D*(log(input)-A)))*B;

the message I get is "the function to be optimized needs to be stateless"

any idea why i get this message and how to solve it?

Fabian

Answer 1

[Arnav]

Hi @Fabian Zeulner,

I understand that you are using Lookup Table Optimizer to optimize the function written in a MATLAB Function Block in Simulink for HDL Code generation. I was able to reproduce the error using the function you provided. The error dialog I received is shown below:

Since the function is already time invariant and stateless, this suggests that the error is due to operations * and / and these need to be converted into element-wise operations.

To convert * and / operations into element-wise operations, you can change the last line to:

T=(C./(D.*(log(input)-A))).*B; 

I hope this might be helpful in resolving your query.

You may refer the following documentation link for more information about Lookup Table Optimizer:

https://www.mathworks.com/help/releases/R2023b/fixedpoint/ref/lookuptableoptimizer-app.html