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

ARMv6 Differences
G.4 Instruction set support
Two instruction sets are supported in ARMv6:
the ARM instruction set
the Thumb instruction set.
ARMv6 floating-point support, known as VFPv2, is the same as that supported in ARMv5. The instructions
use coprocessors 10 and 11 and are documented with all other instructions in Alphabetical list of
instructions on page A8-14. The following VFP instructions are not supported in ARMv6. These
instructions are introduced in ARMv7 (VFPv3):
VMOV (immediate)
VCVT (between floating-point and fixed-point).
Note
VFP instruction mnemonics traditionally started with an F. However this has been changed to a V
prefix in the Unified Assembler Language introduced in ARMv6T2, and in many cases the rest of the
mnemonic has been changed to be more compatible with other instructions mnemonics. This aligns
the scalar floating-point support with the ARMv7 Advanced SIMD support, which shares some
load/store and move operations to a common register file.
The VFPv2 instructions are summarized in F* (former VFP instruction mnemonics) on page A8-100.
This includes the two deprecated instructions in VFPv2 that do not have UAL mnemonics, the FLDMX
and FSTMX instructions.
ARMv6 introduces new instructions in addition to supporting all the ARM and Thumb instructions available
in ARMv5TEJ. For more information, see Instruction set support on page AppxH-11, ARM instruction set
support on page AppxG-11, and Thumb instruction set support on page AppxG-14.
The ARM and Thumb instruction sets grew significantly in ARMv6 and ARMv6T2, compared with
ARMv5TEJ, mainly because of:
the development of ARMv6 SIMD
the addition of many 32-bit Thumb instructions in ARMv6T2.
ARMv6K adds some kernel support instructions. It also permits the use of the optional Security Extensions
and the SMC instruction.
ARMv7 extends the instruction sets as defined for ARMv6 and the ARMv6 architecture variants and
extensions as follows:
the introduction of barrier instructions to the ARM and Thumb instruction sets
the ThumbEE extension in ARMv7
the new instructions added in VFPv3
the Advanced SIMD extension in ARMv7.
AppxG-10 Copyright © 1996-1998, 2000, 2004-2008 ARM Limited. All rights reserved. ARM DDI 0406B