The invention relates to a device comprising a processor, the processor comprising: an execution unit for executing multiple threads, each thread comprising a sequence of instructions; and a plurality of sets of thread registers, each set arranged to store information relating to a respective one of the plurality of threads. The processor also comprises circuitry for establishing channels between thread register sets, the circuitry comprising a plurality of channel terminals and being operable to establish a channel between one of the thread register sets and another thread register set via one of the channel terminals and another channel terminal. Each channel terminal comprises at least one buffer operable to buffer data transferred over a thus established channel and a channel terminal identifier register operable to store an identifier of the other channel terminal via which that channel is established.