Why do i get an error in the Fixed Point Conversion Step?

1 view (last 30 days)
Error: The function 'HDLIFFT128' contains persistent variables 'ifft128' and has specialization 'HDLIFFT128_s1' associated with it. Function specializations containing persistent variables are not supported for fixed-point conversion. Consider rewriting your algorithm such that it does not use persistent variables within functions that require specialization.
I am trying to generate HDL Code from this main function.
function [out1,out2] = main(x,y,z)
%call subfunction 1
out1 = sub1(x);
%call subfunction 2
out2 = sub2(y,z);
end
Sub-function 2 code:
function [yOut,validOut] = HDLIFFT128(yIn,validIn)
%HDLIFFT128
% Processes one sample of data using the dsp.HDLIFFT System object(TM)
% yIn is a fixed-point scalar or column vector.
% validIn is a logical scalar.
% You can generate HDL code from this function.
persistent ifft128;
if isempty(ifft128)
ifft128 = dsp.HDLIFFT('FFTLength',128);
end
[yOut,validOut] = step(ifft128,yIn,validIn);
end

Accepted Answer

Walter Roberson
Walter Roberson on 13 Jul 2016
I would suggest breaking it up into two pieces, one of which constructs the ifft128 object, and the other of which expects that object to be always input.
  3 Comments

Sign in to comment.

More Answers (1)

Bharath Venkataraman
Bharath Venkataraman on 13 Jul 2016
Pablo, splitting the function into a main function and calling the IFFT function from it resulted in HDL code generation. Here are the functions split up. Please replace the testbench and design files as needed.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!