In reply to KillSteal:
This code is failing for randomization issue only with Questa simulator in EDAPlayground and for all other simulators it’s passing.
Until end_addr>= start_addr ; constraint solver solves this constraint. When start_addr>=end_addr constraint will fail.
Just if we add below constraint , not seeing any constraint issue with Questasim also.
constraint add_2_range{end_addr >= start_addr ;}
But as Dave mentioned, it’s not generating cyclic values with randc variables. THis may be some tool specific.