ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition

Glossary
Abort Is caused by an illegal memory access. Aborts can be caused by the external memory system or the MMU
or MPU.
Abort model
Describes what happens to the processor state when a Data Abort exception occurs. Different abort models
behave differently with regard to load/store instructions that specify base register write-back. For more
details, see Effects of data-aborted instructions on page B1-57.
Addressing mode
Means a method for generating the memory address used by a load/store instruction.
Advanced SIMD
Is an extension to the ARM architecture that provides SIMD operations on a bank of extension registers. If
the VFP extension is also implemented, the two extensions share the register bank and the SIMD operations
include single-precision floating-point SIMD operations.
Aligned Refers to data items stored in such a way that their address is divisible by the highest power of 2 that divides
their size. Aligned halfwords, words and doublewords therefore have addresses that are divisible by 2, 4 and
8 respectively.
An aligned access is one where the address of the access is aligned to the size of an element of the access
ARM instruction
Is a word that specifies an operation for a processor in ARM state to perform. ARM instructions must be
word-aligned.
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