How to generate random delay in "generate" loop?

Hi,
How can I generate random time delay in following code? What I found so 
far is only random generation in a process with function "uniform". I 
want to generate random time delays during compile time. Is it possible?

Thanks.

1

  for i in 0 to nr_entries-1 generate    

2

    multiple_n: w_entity 

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      generic map (delay => (i+1) * 1 ps , chain_len => nr_chains) -- Delay must be "random" from 100 to 300 ps

4

      port map (

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        rst_i => s_rst,

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        out_o => s_inp(i)

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      );

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  end generate;

I am now generating it from for-variable "i" which is not random.