Address lookup is one of the main bottlenecks in Internet backbone routers, as it requires the router to perform a longest-prefix-match when searching the routing table for a next hop. Ever-increasing Internet bandwidth, continuously growing prefix table size and inevitable migration to IPv6 address architecture further exacerbate this situation. In recent years, a variety of high-speed address lookup algorithms have been proposed, however most of them are inappropriate to IPv6 lookup. This paper proposes a high-speed IPv6 lookup algorithm TrieC, which achieves the goals of high-speed address lookup, fast incremental prefix updates, high scalability and reasonable memory requirement by taking great advantage of the network processor architecture. Performance of TrieC is carefully evaluated with several IPv6 routing tables of different sizes and different prefix length distributions on Intel IXP2800 network processor(NPU). Simulation shows that TrieC can support IPv6 lookup at OC-192 line rate. Furthermore, if TrieC is pipelined in hardware, it can achieve one IPv6 lookup per memory access.