Abstract: With increasing integration of system on chip (SoC),communication between IP cores become an urgent problem．In recent years,network on chip (NoC) has been proposed as an effective solution to the complex on-chip communication problems．Virtual channel and routing algorithm play an important role in NoC design．They have great impact on latency,throughput and other performance of NoC．According to the characteristics of load distribution of NoC,we presented a novel non-uniform distribution technology of virtual channel (VCND)．The technology of virtual channel is used in the internal Mesh and non-virtual channel is used on the boundary of Mesh．Hence,the amount of buffer unit is reduced．Then a modified deadlock-free routing algorithm was proposed,called combination XY (CXY)．Simulation results show that CXY routing algorithm can improve network throughput and keep low message latency compared with XY and XY-YX routing algorithms．And VCND can save router’s area and increase the utilization rate of buffer unit obviously with a little losing of network throughput and latency,compared with uniform distribution technology of virtual channel．

Key words: Network on chip,Virtual channel,Routing algorithm