Found an unsupported unbounded loop structure.

Hello there, I'm working at a very long program, and I got the following error, when I tried to convert it to HDL coder.

The program successfully passed the fixed point conversion, but still I got the following while I converting it to HDL code.

the biggest problem is Matlab can't point which loop has this problem. but it says

### HDL Conformance check complete with 2 errors, 0 warnings, and 0 messages.

"Found an unsupported unbounded loop structure. This loop may be user written or automatically generated due to the use of specific vector expressions or functions. For more information on unsupported loop structures, please refer to the documentation."

here is my code:

 for nj=1:2:228
    if (UPDN(toll2(nj))==1 && beh(toll2(nj))==1);  
        for tp=toll2(nj):1:toll2(nj+1);  
            Combined_S7_tam(tp)=Combined_S7(tp);        
        end
      nj=nj+1;
        for tp=toll2(nj):1:toll2(nj+1);
        Combined_S7_tam(tp)=DAC_shift(tp);
        end
    end

    nj=nj+1;
end

[Walter Roberson]

duplicates http://uk.mathworks.com/matlabcentral/answers/222369-found-an-unsupported-unbounded-loop-structure