x86 Instruction Set Reference

MOVZX

Move with Zero-Extend

Opcode	Mnemonic	Description
`0F B6 /r`	`MOVZX r16,r/m8`	Move byte to word with zero-extension.
`0F B6 /r`	`MOVZX r32,r/m8`	Move byte to doubleword, zero-extension.
`0F B7 /r`	`MOVZX r32,r/m16`	Move word to doubleword, zero-extension.

Description
Copies the contents of the source operand (register or memory location) to the destination operand (register) and zero extends the value to 16 or 32 bits. The size of the converted value depends on the operand-size attribute.

Operation
Destination = ZeroExtend(Source);

Flags affected
None.

Protected Mode Exceptions

`#GP(0)`	If a memory operand effective address is outside the CS, DS, ES, FS, or GS segment limit. If the DS, ES, FS, or GS register contains a null segment selector.
`#GP(0)`	If a memory operand effective address is outside the CS, DS, ES, FS, or GS segment limit. If the DS, ES, FS, or GS register contains a null segment selector.
`#SS(0)`	If a memory operand effective address is outside the SS segment limit.
`#PF(fault-code)`	If a page fault occurs.

Real-Address Mode Exceptions

`#GP`	If a memory operand effective address is outside the CS, DS, ES, FS, or GS segment limit.
`#GP`	If a memory operand effective address is outside the CS, DS, ES, FS, or GS segment limit.

Virtual-8086 Mode Exceptions

`#GP(0)`	If a memory operand effective address is outside the CS, DS, ES, FS, or GS segment limit.
`#GP(0)`	If a memory operand effective address is outside the CS, DS, ES, FS, or GS segment limit.
`#SS(0)`	If a memory operand effective address is outside the SS segment limit.
`#PF(fault-code)`	If a page fault occurs.

Instruction	Latency	Throughput	Execution Unit
`CPUID`	0F3n/0F2n	0F3n/0F2n	0F2n
`MOVZB/MOVZW`	1/0.5	0.5/0.5	ALU