3-414
INSTRUCTION SET REFERENCE
MOVDMove 32 Bits
Description
This instruction copies doubleword from source operand (second operand) to destination
operand (first operand). Source and destination operands can be MMX technology registers,
memory locations, or 32-bit general-purpose registers; however, data cannot be transferred from
an MMX technology register to another MMX technology register, from one memory loca-
tion to another memory location, or from one general-purpose register to another general-
purpose register.
When the destination operand is an MMX technology register, the 32-bit source value is
written to the low-order 32 bits of the 64-bit MMX technology register and zero-extended to
64 bits (refer to Figure 3-41). When the source operand is an MMX technology register, the
low-order 32 bits of the MMX technology register are written to the 32-bit general-purpose
register or 32-bit memory location selected with the destination operand.
Opcode
Instruction
Description
0F 6E /r
MOVD mm, r/m32Move doubleword from r/m32 to mm.
0F 7E /r
MOVD r/m32, mmMove doubleword from mm to r/m32.
Figure 3-41. Operation of the MOVD Instruction
MOVD m32, mm
MOVD mm, r32
63
31
0
3231
mm
m32
150
0
00000000
bbbbr32
bbbb
63
mm
0
xxxxxxxx
bbb
bb
bb
W
W
3006010
3231
3210
3
0
1
2N+1
N+1
3210
b
3210
