A mechanism receives memory reads and writes from a packet processing engine, each memory access having an associated packet identifier or sequence number. The mechanism is placed between the packet processing engine and a memory system such that write data is buffered and information based upon both reads and writes is recorded. Information is maintained allowing the detection of memory conflicts. Both a strict and alternate packet ordering are evaluated, such that the semantic ordering of packets is delayed until necessary to ensure that a consistent order exists. Such a late order binding mechanism is used to allow packets to be defined in any order so long as they obey a consistent order, thereby reducing the number of packet restarts and increasing overall efficiency.