Recent advances on language based software toolkit generation enables performance driven exploration of embedded systems by exploiting the application behavior. There is a need for an automatic generation of hardware to determine the required silicon area, clock frequency, and power consumption of the candidate architectures. In this paper, we present a language based exploration framework that automatically generates synthesizable RTL models for pipelined processors. Our framework allows varied micro-architectural modifications, such as, addition of pipeline stages, pipeline paths, opcodes and new functional units. The generated RTL is synthesized to determine the area, power, and clock frequency of the modified architectures. Our exploration results demonstrate the power of reuse in composing heterogeneous architectures using functional abstraction primitives allowing for a reduction in the time for specification and exploration by at least an order of magnitude.