A.101 B.110 C.100 D.111
A.00011001101 B.10001100110 C.01100110001 D.00110011001
A.模式0 B.模式1 C.模式2 D.模式5
A.-127～+127 B.-127～+128 C.-128～+127 D.-128～+128
A.0 B.1 C.2 D.3
