dmb

Data Memory Barrier

DMB <option>

Ensures memory access ordering.

Details

Data Memory Barrier instruction that ensures all memory accesses before this instruction are observed before any memory accesses after it. The option field specifies the scope (SY for full system, ISH for inner shareable, NSH for non-shareable, etc.). No register changes or flags are affected. Available in AArch64, A32, and T32.

Pseudocode Operation

Barrier(option)

Example

DMB option

Encoding

Binary Layout

11010101000000110011

CRm

11111

Format System

Opcode 0xD50330BF

Extension Base

Operands

option
Barrier type (SY, ISH, etc)

Reference (Arm A64 ISA)

Instruction Forms

Encoding	Instruction		ISA		Bit pattern
0xD50330BF	DMB (<option>\|#<imm>)		A64		11010101000000110011 \| CRm \| 1 \| 01 \| 11111

Description

Data Memory Barrier is a memory barrier that ensures the ordering of observations of memory accesses, see Data Memory Barrier.

Operation

DataMemoryBarrier(domain, types);