Topological entropy of periodic coven cellular automata

We investigate topological entropy of periodic Coven cellular automatas; that is, the maps FB:Z{0,1}→Z{0,1} defined by where B=b1b2…br∈r{0,1}(r≥2), is a periodic word. In particular, we prove that if the minimal period of B is greater than , the topological entropy is log 2.