Constraint Randomization of an Array : No consecutive bits should be one and No of ones should be 12

SystemVerilog
,
9

In reply to mavcdn:

The constraint


foreach (test_ones[i]) {if (i != 31) ( (test_ones[i] != test_ones[i+1]));}

means test_ones will have a repeating 2’b01 or 2’b10 pattern, and there will be 16 ones and 16 zeroes. That is in conflict with the other constraint

$countones(test_ones) == 12;

and so you get a constraint failure.