UM10429
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User manual
Rev. 1 — 20 October 2010
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NXP Semiconductors
UM10429
Chapter 19: Appendix LPC1102 ARM Cortex-M0 reference
19.4.7.2.3
Restrictions
There are no restrictions.
19.4.7.2.4
Condition flags
This instruction does not change the condition flags.
19.4.7.2.5
Examples
CPSID i ; Disable all interrupts except NMI (set PRIMASK)
CPSIE i ; Enable interrupts (clear PRIMASK)
19.4.7.3 DMB
Data Memory Barrier.
19.4.7.3.1
Syntax
DMB
19.4.7.3.2
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 observed before any explicit
memory accesses that appear in program order after the DMB instruction. DMB does not
affect the ordering of instructions that do not access memory.
19.4.7.3.3
Restrictions
There are no restrictions.
19.4.7.3.4
Condition flags
This instruction does not change the flags.
19.4.7.3.5
Examples
DMB
; Data Memory Barrier
19.4.7.4 DSB
Data Synchronization Barrier.
19.4.7.4.1
Syntax
DSB
19.4.7.4.2
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.
19.4.7.4.3
Restrictions
There are no restrictions.