Special session on “Exposed data path architectures: Recent advances and applications”

The concept of “exposed datapath” is used in conjunction with processor architectures where the programmer can control more fine grained details of the datapath than in “traditional” processor architectures. For example, Transport Triggered Architectures (TTA) expose the data transports between the register files and function units for the direct control of the programmer. Some architectures, while otherwise having a general purpose register based instruction-set, allow the programmer to explicitly route previously computed results from a function unit to the next one to implement register bypassing in software. The additional datapath control extends the instruction scheduling freedom, simplifies the control hardware logic, eases the customization of the datapath interconnection network, and increases the instruction-level parallelism scalability, with the obvious drawbacks of wider instruction words and added compilation complexity.