NASM 2.05 based x86 Instruction Reference[ch183]
A.5.161 MOVDQA: Move Aligned Double Quadword MOVDQA xmm1,xmm2/m128 ; 66 OF 6F /r [WILLAMETTE,SSE2] MOVDQA xmm1/m128,xmm2 ; 66 OF 7F /r [WILLAMETTE,SSE2] MOVDQA moves a double quadword from the source operand to the destination operand. When the source or destination operand is a memory location, it must be aligned to a 16-byte boundary. To move a double quadword to or from unaligned memory locations, use the MOVDQU instruction (section A.5.162).