An apparatus comprising a plurality of signal processors, a master processor, and a plurality of memories, each signal processor having write access at any time to only a particular one of said memories and read access at any time to any of said memories, wherein at least one of said signal processors in said plurality operates independently of other signal processors in said plurality of signal processors, and
- wherein said signal processors provide a respective indication signal to said master processor so as to notify said master processor that newly-written-in data can be obtained from one or more of said plurality of memories.