Datasheet

SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
144
10.18.3 DMB
Data Memory Barrier.
10.18.3.1 Syntax
DMB{cond}
where:
cond is an optional condition code, see “Conditional execution” on page 91.
10.18.3.2 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.
10.18.3.3 Condition flags
This instruction does not change the flags.
10.18.3.4 Examples
DMB ; Data Memory Barrier
10.18.4 DSB
Data Synchronization Barrier.
10.18.4.1 Syntax
DSB{cond}
where:
cond is an optional condition code, see “Conditional execution” on page 91.
10.18.4.2 Operation
DSB acts as a special data synchronization memory barrier. Instructions that come after the DSB, in program
order, do not execute until the DSB instruction completes. The DSB instruction completes when all explicit memory
accesses before it complete.
10.18.4.3 Condition flags
This instruction does not change the flags.
10.18.4.4 Examples
DSB ; Data Synchronisation Barrier