This paper presents a new routing protocol of network-on-chip(Noc) called "Source Routing for Noc" (SRN) for fault tolerant communication of Systems-on-chip(Soc). The proposed SRN algorithm is composed of two mechanisms of Route Discovery and Route maintenance to allow nodes to discover and maintain source routes to arbitrary destinations in Noc, and all aspects of the protocol operate entirely on-demand allowing the routing packet overhead to scale automatically based on its need. The SNR algorithm in this paper demonstrates up to 50 % more fault tolerance comparing with the conventional algorithms. This new method can be easily adapted and implemented with lower cost due to less hardware overhead in SoC that integrate a large number of communicating IP cores.