In reply to sharvil111:
Yes, I am using the VCS tool only and here is my code:
module test();
class Packet;
rand byte a,b[10],c;
constraint ab {unique {a,b[2:5],c};}
constraint c1{c==5;}
endclass
Packet p=new();
initial begin
repeat(10)
if(p.randomize()) $display("%p",p);
endmodule
Output:
“file.sv”, 8: token is ‘unique’
constraint ab {unique {a,b[2:5],c};}
^
System verilog keyword ‘unique’ is not expected to be used in this context.