error in conversion to hdl code"Persistent variable 'y' must be assigned before it is used. The only exception is a check using 'isempty(y)' that can be performed prior to assignment."

hello i am trying to convert the following code into hdl but i am receiving the above error please help me with this. my input is [20385 1] and output 200

function result_k1 = tryf_fixpt(sout2)
%#codegen
persistent y
window_width=50;
if isempty(y)
for j=1:200
        window_m1=sout2((j:window_width+(j-1)));  
        window_m11=window_m1(:);
        y(j)=skewness(window_m11);
end
end     
result_k1=fi(y);

Answer 1

[Kiran Kintali]

You have too much IO on the DUT.

(20385 + 200)*dataWordLength ==> too many IO pins.

Either you need to stream the inputs and outputs manually as shown in this example

https://www.mathworks.com/help/hdlcoder/ug/image-enhancement-by-histogram-equalization.html

or consider automatic IO optimization described below.

HDL Code Generation from Frame-Based Algorithms

https://www.mathworks.com/help/hdlcoder/ug/frame-to-sample-or-pixel-conversion-to-target-stream-based-hardware.html