DARSIM is a parallel cycle-level simulator for network-on-chip (NoC) architectures. It simulates an on-chip network based on the classical wormhole NoC router  and a built-in MIPS core simulator; alternately, it can be driven with application traces. Darsim's flexible, table-based routing and VC allocation scheme allows many complex routing algorithms to be implemented out of the box.
 W. J. Dally and B. Towles. Principles and practices of interconnection networks. Morgan Kaufmann, 2003.