3.12.4. DMB

Data Memory Barrier.

Syntax

DMB{cond} {opt}

Where:

cond

Is an optional condition code. See Conditional execution.

opt

Specifies an optional limitation on the DMB operation. Values are:

SY

DMB operation ensures ordering of all accesses, encoded as opt == '1111'. Can be omitted.

All other encodings of opt are reserved. The corresponding instructions execute as system (SY) DMB operations, but software must not rely on this behavior.

Operation

DMB acts as a data memory barrier. It ensures that all explicit memory accesses that appear, in program order, before the DMB instruction are completed before any explicit memory accesses that appear, in program order, after the DMB instruction. DMB does not affect the ordering or execution of instructions that do not access memory.

Condition flags

This instruction does not change the flags.

Examples

    DMB  ; Data Memory Barrier 

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