関連ワード:  implement 4 * 16 decoder using two 3 * 8 decoders    4*16 decoder using two 3*8 decoder    3 to 8 decoder using 1 to 2 decoder    3 to 8 decoder using 2 to 4 decoder  
結果 : implement 4 * 16 decoder using two 3 * 8 decoders