Design of coherence verification unit for heterogeneous CMPs

In embedded system-on-a-chip (SoC) applications, the demand for integration of heterogenous processors on a single chip is increasing. It adds complexity in maintaining coherency in data caches of the heterogeneous processors implementing different coherence protocols. Therefore, the task of coherence verification also becomes non-trivial for such a system. This work proposes an effective solution for coherence verification in heterogenous CMPs system through introduction of a highly efficient verification unit. The proposed design exploits the modular structure of Cellular Automata (CA), an autonomous machine. A CA is segmented to employ one segment to analyze the states of a data block in different private caches of a homogeneous processor cluster of SoC and the outcome of coherence verification for clusters are analyzed by the CA resulted out of augmentation of the CA segments. The simple hardware implementation of the CA based design realizes quick decision on the cache coherency in heterogenous CMPs with 100% accuracy.