Generate unique elements in an array

In reply to dave_59:

Ok I have declared it as an associative array.
I actually need 2**DCD_INDEX_BITS as my array depth. But if I say [DCD_INDEX_BITS-1:0], the array depth would be 2 items only.

I also need to generate something like:

DCD PDW
0 3, 4, 5, 6, 8, 9, 49, 50
1 51, 63, 54, 45, 0, 1, 33, 11

So for each DCD I neeed to generate 8-pdw values, such that the PDW values for a DCD should not be repeated for any other DCD.