Enabled by the continuous advancement in fabrication technology, present day synchronous microprocessors include more than 100 million transistors and have clock speeds well in excess of the 1GHz mark. Distributing a low-skew clock signal in this frequency range to all areas of a large chip is a task of growing complexity. As a solution to this problem, designers have recently suggested the use of frequency islands that are locally clocked and externally communicate using mixed timing communication schemes. Such a design style fits nicely the recently proposed concept of voltage islands that, in addition, can potentially enable fine grain dynamic power management. This paper proposes a design exploration framework for application-adaptive multiple clock processors which provides the means for analyzing and identifying the right inter-domain communication scheme and the proper granularity for the choice of voltage/frequency. In addition, the proposed design exploration framework allows...