A given DSP, when processing signals of a channel, stores channel instance data in a multiplexed memory in association with itself. If the channel processing task changes to one for which the given DSP is not optimised, the given DSP moves the channel to an appropriate new DSP. Additionally, the given DSP transfers the association of the channel instance data to an association with the new DSP. In this way, the new DSP is provided with the channel instance data without the requirement for physically transferring such data.