NASM 2.05 based x86 Instruction Reference[ch181]
A.5.159 MOVD: Move Doubleword to/from MMX Register MOVD mm,r/m32 ; 0F 6E /r [PENT,MMX] MOVD r/m32,mm ; 0F 7E /r [PENT,MMX] MOVD xmm,r/m32 ; 66 0F 6E /r [WILLAMETTE,SSE2] MOVD r/m32,xmm ; 66 0F 7E /r [WILLAMETTE,SSE2] MOVD copies 32 bits from its source (second) operand into its destination (first) operand. When the destination is a 64-bit MMX register or a 128-bit XMM register, the input value is zero-extended to fill the destination register.