You copied the Doc URL to your clipboard.


Transfer between two general-purpose registers and a 40-bit internal accumulator.

MRA{ cond } RdLo , RdHi , Acc



is an optional condition code.


is the internal accumulator. The standard name is accx,where x is an integer in the range 0 to n. The value of n depends on the processor. It is 0 for current processors.

RdLo, RdHi

are general-purpose registers. RdLo and RdHi must not be the PC, and they must be different registers.


The MRA instruction:

  • Copies bits[31:0] of Acc to RdLo.

  • Copies bits[39:32] of Acc to RdHi bits[7:0].

  • Sign extends the value by copying bit[39] of Acc to bits[31:8] of RdHi.


The MRA ARM coprocessor 0 instruction is only available in XScale processors.

There is no Thumb version of the MRA instruction.


    MRA     r4, r5, acc0
    MRAGT   r4, r8, acc0