11.61 MRC and MRC2

Move to ARM Register from Coprocessor. Depending on the coprocessor, you might be able to specify various additional operations.

Syntax

MRC{cond} coproc, #opcode1, Rt, CRn, CRm{, #opcode2}

MRC2{cond} coproc, #opcode1, Rt, CRn, CRm{, #opcode2}

where:

cond

is an optional condition code. In ARM code, cond is not permitted for MRC2.

coproc

is the name of the coprocessor the instruction is for. The standard name is pn, where n is an integer in the range 0 to 15.

opcode1

is a 3-bit coprocessor-specific opcode.

opcode2

is an optional 3-bit coprocessor-specific opcode.

Rt

is the ARM destination register. Rt must not be PC.

Rt can be APSR_nzcv. This means that the coprocessor executes an instruction that changes the value of the condition flags in the APSR.

CRn, CRm

are coprocessor registers.

Usage

The use of these instructions depends on the coprocessor. See the coprocessor documentation for details.

Architectures

The MRC ARM instruction is available in all versions of the ARM architecture.

The MRC2 ARM instruction is available in ARMv5T and above.

These 32-bit Thumb instructions are available in ARMv6T2 and above.

There are no 16-bit versions of these instructions in Thumb.

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