Towards Purposeful Design Space Exploration of Heterogeneous CGRAs: Clock Frequency Estimation

Coarse Grained Reconfigurable Arrays become increasingly popular. Besides research on scheduling algorithms and microarchitecture concepts, the use of heterogeneous structures can be a key approach to exploit their full potential. Unfortunately, a purposeful design space exploration of CGRAs is not trivial, since one needs to know the clock frequency of the resulting hardware implementation. This paper discusses challenges and a statistical approach to maximum clock frequency estimation of heterogeneous CGRAs with an irregular interconnect on FPGAs. The presented approach allows estimation with a maximum error of 8.8 - 17.4% and a mean error of only 1.9 - 4.6%.