Networks on silicon: blessing or nightmare?

Continuing VLSI technology scaling raises several deep submicron (DSM) problems like relatively slow interconnect, power dissipation and distribution, and signal integrity. Those problems are encountered particularly on long wires for global interconnect. As clock frequencies increase, scaled wires become relatively slower and on-chip communication will be the limiting performance factor of future chips. We explain why efficiently sharing of the wires for long distance communication is the solution to this problem. We introduce networks on silicon (NoS), that route packets over shared (semi)-global wires. NoS performance is expected to be high, but comes at a cost. Balancing the performance and cost of a NoS is a major challenge, and we believe busses still have a role to play.