6.3. Word Registers
16-bit registers via WordReg access the lower 16 bits:
#check AX -- Lower 16 bits of EAX
#check DX -- Lower 16 bits of EDX
16-bit registers via WordReg access the lower 16 bits:
#check AX -- Lower 16 bits of EAX
#check DX -- Lower 16 bits of EDX