Accelerating the Rijndael algorithm using custom instructions capability of Nios II in ODYSSEY

The ODYSSEY design methodology is an object-oriented design methodology which models a system in terms of its constituting objects and their corresponding method calls. Some of these method calls are implemented in hardware functional units, while others are simply executed by a general-purpose processor. There is a communication overhead because functional units must communicate with each other and with the processor core. In this paper the authors utilize the custom instructions capability of Nios II processor to enhance the performance of the ASIP. Since these instructions are in the processor itself, there is no communication overhead for using them. The authors analyze the performance of the proposed method by implementing the Rijndael algorithm with and without this capability, and show the achieved speedup