General purpose processors provide a well performance with adequate power consumption for a huge bandwidth of applications in average. However, most embedded systems target a very narrow or even single application domain which would benefit from a specific processor, optimized for this scenario in order to gain performance and to reduce power consumption. But the development of application specific processors for each application is a time consuming task and often not feasible for developers due to the missing toolsets or experience in processor design. This paper introduces a novel approach for a processor core, which is able to adapt its micro architecture in relation to the application requirement. In general, the processor starts in a general purpose mode and migrates while run-time to a special purpose processor by adapting its micro architecture. The paper introduces this novel processor approach which is called i-core and presents first experimental results.