Arm Compiler armasm User Guide : 14.5 Alignment restrictions in load and store element and structure instructions

14.5 Alignment restrictions in load and store element and structure instructions

Many of these instructions allow you to specify memory alignment restrictions.

When the alignment is not specified in the instruction, the alignment restriction is controlled by the A bit (SCTLR bit[1]):

If the A bit is 0, there are no alignment restrictions (except for strongly-ordered or device memory, where accesses must be element-aligned).
If the A bit is 1, accesses must be element-aligned.

If an address is not correctly aligned, an alignment fault occurs.

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