In general, in one aspect, the disclosure describes a processing unit that includes a datapath having an input buffer, at least one memory, and an arithmetic logic unit, and control logic having access to a program instruction control store. The control logic controls operation of the datapath and may concurrently cause the datapath to operate in response to different instructions that use different sections of the datapath, wherein the different sections of the datapath comprise a first section transferring data from an input buffer to the memory and a second section transferring data from the memory to the arithmetic logic unit.