Removing Context Memory from a Multi-context Dynamically Reconfigurable Processor
Hideharu Amano, Masayuki Kimura, Nobuaki Ozaki · 2012
Although context memory or configuration cache is a key mechanism for quick dynamic reconfiguration of multi-context Dynamically Reconfigurable Processing Array (DRPA), it requires a large amount of area and energy. In order to save them, methods to remove the context memory from multi-context DRPA are proposed. In order to keep a context without switching, Loop Separation for Keeping Datapath (LSKD)is introduced. By separating loops by the compiler and some additional hardware, the same context can be used without switching in a certain clock cycles. The back-ground configuration data loading time can be reduced by multicasting configuration data with two dimensional bit-map. For further reduction, the differential loading and spare register are proposed. With combination of them, the increasing execution time is only up to 12-13% if the target application does not have loop-carried dependency. With the above overhead on the performance, the semiconductor area becomes 63%, and the energy consumption is reduced to 40%, thus, the performance per cost or energy is much improved.