Instruction Set(quick finder) |
ARM 2 ARM 3 ARMv2 | ARM 2 or ARM 3 |
ARMv3 | ARM6xx or ARM7xx |
ARMv4 | StrongARM |
ARMv5 | ARM9, XScale, etc |
Floating Point | Hardware or (usually) software floating point, from ARM 2 (software) to ARM7500FE (mostly hardware). No RISC floating point unit is entirely hardware, it is a balance between basic FP instructions in hardware, and more complex things (like RMF) in software. |
VFP | Vector Floating Point, in ARMv5 (etc) processors |
Thumb | 16 bit-ised version of ARM as an option in ARMv5 (etc) processors |
For the full range, refer to the ARM Ltd documentation. |
Instruction | Meaning | Earliest CPU / Comments
|
ABS | Absolute Value | Floating Point 1
|
ACS | Arc Cosine | Floating Point 5
|
ADC | Add with Carry | -
|
ADC | Thumb: Add with Carry | Thumb
|
ADD | Add | -
|
ADD | Thumb: Add | Thumb
|
ADF | Add | Floating Point 1 3
|
ADR | Get address of object (within 4K) | This is an assembler pseudo-instruction
|
ADRL | Get address of object (beyond 4K) | This is an assembler pseudo-instruction
|
ALIGN | Set the program counter to the next word boundary | This is an assembler pseudo-instruction
|
AND | Logical AND | -
|
AND | Thumb: Logical AND | Thumb
|
ASL | Arithmetic Shift Left | This is an option, not an instruction
|
ASN | Arc Sine | Floating Point 5
|
ASR | Arithmetic Shift Right | This is an option, not an instruction; available on Thumb. |
ATN | Arc Tangent | Floating Point 5
|
B | Branch | -
|
B | Thumb: Branch | Thumb
|
BIC | Bit Clear | -
|
BIC | Thumb: Bit Clear | Thumb
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BKPT | Thumb: Breakpoint | Thumb
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BL | Branch with Link | -
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BL | Thumb: Long Branch with Link | Thumb
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BLX | Thumb: Branch with Link and Exchange | Thumb
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BX | Thumb: Branch and Exchange | Thumb
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CDP | Co-processor data operation | -
|
CDP2 | CDP, non-conditional so more co-processor commands possible | ARMv5
|
CLZ | Count Leading Zeros | ARMv5
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CMF | Compare floating point value | Floating Point 1 3
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CMN | Compare negated values | -
|
CMN | Thumb: Compare negated values | Thumb
|
CMP | Compare values | -
|
CMP | Thumb: Compare values | Thumb
|
CNF | Compare negated floating point values | Floating Point 1
|
COS | Cosine | Floating Point 5
|
DCx | Define byte (B), halfword (W), word (D), string (S), or floating point (F) value. Some assemblers allow DCFS, DCFD, etc for FP precision. | This is an assembler pseudo-instruction
|
DVF | Divide | Floating Point 1 3
|
EOR | Exclusive-OR two values | -
|
EOR | Thumb: Logical Exclusive-OR | Thumb
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EQUx | Define byte (B), halfword (W), word (D), string (S), or floating point (F) value. Some assemblers allow EQUFS, EQUFD, etc for FP precision. | This is an assembler pseudo-instruction
|
EXP | Exponent | Floating Point 5
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FABS | VFP: Absolute | VFP
|
FADD | VFP: Addition | VFP
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FCMP | VFP: Compare | VFP
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FCVTDS | VFP: Single to Double | VFP
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FCVTSD | VFP: Double to Single | VFP
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FCPY | VFP: Copy [like MVF] | VFP
|
FDIV | VFP: Division | VFP
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FDV | Fast Divide | Floating Point 1
|
FIX | Convert floating value to an integer | Floating Point 1 3
|
FLD | VFP: Load VFP registers | VFP
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FLDMDB | VFP: Load multiple VFP registers, decr. before | VFP
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FLDMIA | VFP: Load multiple VFP registers, incr. after | VFP
|
FLT | Convert integer to a floating value | Floating Point 1 3
|
FMAC | VFP: Multiply with Accumulate | VFP
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FMDHR | VFP: Transfer ARM register to upper half of Double | VFP
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FMDLR | VFP: Transfer ARM register to lower half of Double | VFP
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FMRDH | VFP: Transfer upper half of Double to ARM register | VFP
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FMRDL | VFP: Transfer lower half of Double to ARM register | VFP
|
FML | Fast multiply | Floating Point 1
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FMSC | VFP: Multiply with Negate and Accumulate | VFP
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FMRS | VFP: Transfer Single to ARM register | VFP
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FMSR | VFP: Transfer ARM register to Single | VFP
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FMUL | VFP: Multiply | VFP
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FMRX | VFP: Transfer VFP system register to ARM register | VFP
|
FMSTAT | VFP: Transfer FPSCR flags to CPSR | VFP
|
FMXR | VFP: Transfer ARM register to VFP system register | VFP
|
FNEG | VFP: Copy Negative [like MVN] | VFP
|
FNMAC | VFP: Multiply with Deduct | VFP
|
FNMSC | VFP: Multiply with Negate and Deduct | VFP
|
FNMUL | VFP: Negative Multiply | VFP
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FRD | Fast reverse divide | Floating Point 1
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FSITO | VFP: Signed Integer to Float | VFP
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FSQRT | VFP: Square Root | VFP
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FST | VFP: Save VFP registers | VFP
|
FSTMDB | VFP: Save multiple VFP registers, decr. before | VFP
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FSTMIA | VFP: Save multiple VFP registers, incr. after | VFP
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FSUB | VFP: Subtraction | VFP
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FTOSI | VFP: Float to Signed Integer | VFP
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FTOUI | VFP: Float to Unsigned Integer | VFP
|
FUITO | VFP: Unsigned Integer to Float | VFP
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LDC | Load from memory to co-processor | -
|
LDC2 | LDC, non-conditional so more co-processor commands possible | ARMv5
|
LDF | Load floating point value | Floating Point 1 3
|
LDM | Load multiple registers | -
|
LDMIA | Thumb: Load multiple registers | Thumb
|
LDR | Load register (32 bit) | -
|
LDR | Thumb: Load register (32 bits?) | Thumb
|
LDRB | Load byte (8 bit) into register | -
|
LDRB | Thumb: Load byte (8 bit) into register | Thumb
|
LDRH | Load halfword (16 bit) into register | StrongARM
|
LDRH | Thumb: Load halfwit (boo!) into register | Thumb
|
LDRSB | Load signed byte (sign + 7 bit) into register | StrongARM
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LDRSB | Thumb: Load signed byte (sign + 7 bit) into register | Thumb
|
LDRSH | Load signed halfword (sign + 15 bit) into register | StrongARM
|
LDRSH | Thumb: Load signed halfword (sign + 15 bit) into register | Thumb
|
LFM | Load multiple floating point values | Floating Point 1
|
LGN | Logarithm to base e | Floating Point 5
|
LOG | Logarithm to base 10 | Floating Point 5
|
LSL | Logical Shift Left | This is an option, not an instruction; available on Thumb. |
LSR | Logical Shift Right | This is an option, not an instruction; available on Thumb. |
MCR | Co-processor register transfer (ARM to co-processor) | -
|
MCR2 | MCR, non-conditional so more co-processor commands possible | ARMv5
|
MCRR | MCR, with two registers transferred at one time | ARMv5TE
|
MLA | Multiply with Accumulate | -
|
MNF | Move negated | Floating Point 1
|
MOV | Move value/register into a register | -
|
MOV | Thumb: Move value/register into a register | Thumb
|
MRC | Co-processor register transfer (co-processor to ARM) | -
|
MRC2 | MRC, non-conditional so more co-processor commands possible | ARMv5
|
MRRC | MRC, with two registers transferred at one time | ARMv5TE
|
MRS | Move status flags to a register | ARM 6
|
MSR | Move contents of a register to the status flags | ARM 6
|
MUF | Multiply | Floating Point 1 3
|
MUL | Multiply | -
|
MUL | Thumb: Multiply | Thumb
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MVF | Move value/float register into a float register | Floating Point 1 3
|
MVN | Move negated | -
|
MVN | Thumb: Move negated | Thumb
|
NEG | Thumb Negate | Thumb
|
NOP | Thumb: No Operation | Thumb
|
NRM | Normalise | Floating Point 1
|
OPT | Select assembly options | This is an assembler pseudo-instruction
|
ORR | Logical OR | -
|
ORR | Thumb: Logical OR | Thumb
|
PLD | PreLoaD | ARMv5
|
POL | Polar Angle | Floating Point 5
|
POP | Thumb: Pop registers from stack | Thumb
|
POW | Power | Floating Point 5
|
PUSH | Thumb: Push registers onto stack | Thumb
|
QADD | Add, saturating | ARMv5E
|
QDADD | Add, double saturating | ARMv5E
|
QDSUB | Subtract, double saturating | ARMv5E
|
QSUB | Subtact, saturating | ARMv5E
|
RDF | Reverse Divide | Floating Point 1
|
RFC | Read FP control register | Floating Point 1 4
|
RFS | Read FP status register | Floating Point 1 3
|
RMF | Remainder | Floating Point 2 3
|
RND | Round to integral value | Floating Point 2 3
|
ROR | Rotate Right | This is an option, not an instruction; available on Thumb. |
RPW | Reverse Power | Floating Point 5
|
RRX | Rotate Right with extend | This is an option, not an instruction
|
RSB | Reverse Subtract | -
|
RSC | Reverse Subtract with Carry | -
|
RSF | Reverse Subtract | Floating Point 1
|
SBC | Subtract with Carry | -
|
SBC | Thumb: Subtract with Carry | Thumb
|
SFM | Store Muliple Floating point values | Floating Point 1
|
SIN | Sine | Floating Point 5
|
SMLA | Signed Multiply with Accumulate of 16 bit * 16 bit values | ARMv5E
|
SMLAL | Signed Long (sign + 63 bit) Multiply with Accumulate | StrongARM
|
SMLAL | Signed Multiply with Accumulate of 16 bit * 16 bit values, result is sign extended to 32 bits, then added to a 64 bit value. | ARMv5E
|
SMLAW | Signed Multiply with Accumulate of 32 bit * 16 bit values | ARMv5E
|
SMUL | Signed Multiply of 16 bit * 16 bit values | ARMv5E
|
SMULL | Signed Long (sign + 63 bit) Multiply | StrongARM
|
SMULW | Signed Multiply of 32 bit * 16 bit values | ARMv5E
|
SQT | Square Root | Floating Point 2 3
|
STC | Co-processor data transfer | -
|
STC2 | STC, non-conditional so more co-processor commands possible | ARMv5
|
STF | Store floating point value | Floating Point 1 3
|
STM | Store multiple registers | -
|
STMIA | Thumb: Store multiple registers | Thumb
|
STR | Store a register (32 bit) | -
|
STR | Thumb: Store register (32 bit?) | Thumb
|
STRB | Store a byte (8 bit) from a register | -
|
STRB | Thumb: Store byte (8 bit) | Thumb
|
STRH | Store a halfword (16 bit) from a register | StrongARM
|
STRH | Thumb: Store halfword (16 bit) | Thumb
|
STRSB | Store a signed byte (sign + 7 bit) from a register | StrongARM
|
STRSH | Store a signed half-word (sign + 15 bit) from a register | StrongARM
|
SUB | Subtract | -
|
SUB | Thumb: Subtract | Thumb
|
SUF | Subtract | Floating Point 1 3
|
SWI | Cause a SoftWare Interrupt | -
|
SWI | Thumb: SoftWare Interrupt | Thumb
|
SWP | Swap register with memory | ARM 3
|
TAN | Tangent | Floating Point 5
|
TEQ | Test Equivalence (notional EOR) | -
|
TST | Test bits (notional AND) | -
|
TST | Thumb: Test bits | Thumb
|
UMLAL | Unsigned Long (64 bit) Multiply with Accumulate | StrongARM
|
UMULL | Unsigned Long (64 bit) Multiply | StrongARM
|
URD | Unnormalised round | Floating Point 1
|
WFC | Write FP control register | Floating Point 1 4
|
WFS | Write FP status register | Floating Point 1 3
|
Instructions in bold are the core ARM instructions.
Instructions in italics are provided by the Floating Point Accelerator/Emulator.
Instructions in Dark Grey italics are miscellaneous ARMv5 instrctions.
Instructions in Dark Slate Grey italics are VFP or Thumb instructions.
Everything else are bits and pieces that were worth including, shift options and common assembler mnemonics...
Co-processor instructions are listed. However the ARM processors used in RISC OS machines do not support co-processors, and only the virtual co-processor functions present within the chip can be accessed. These provide facilities for setting up the ARM, cache, MMU, etc...
The Thumb instructions are a subset of the normal ARM instructions, designed to work in a 16 bit mode. This allows more code in less memory, and for cheaper memory subsystems to be used. It is a compromise between the ARM's 32 bit power, and cost-effectiveness.
Before you scratch your head and think "Huh? But DIMMs are cheap!", remember life is rather different when we are talking of specialist embedded devices, ranging from spacecraft to mobile phones. Anyway, some instructions, like STR and MOV are duplicated for the Thumb instructions so there's no ambiguity.
The Vector Floating Point appears to be a superset of the hardware components of the original FPU. Things like POW and COS are not present, as they can be done with software assistance - it would not be in keeping with RISC principles to devote silicon to things like that.