mcr

Move to Coprocessor from Register (A32)

MCR<c> <coproc>, <opc1>, <Rt>, <CRn>, <CRm>{, <opc2>}

Writes a general-purpose register to a coprocessor register (e.g., CP15).

Pseudocode Operation

if ConditionPassed(cond) then
  CP[coproc, opc1, CRn, CRm, opc2] ← Rt

Example

MCR p15, 0, r3, c1, c2

Encoding

Binary Layout

cond

31:28

1110

27:24

opc1

23:21

CRn

19:16

15:12

111

11:9

coproc<0>

opc2

7:5

CRm

3:0

Format Coprocessor

Opcode 0x0E000E10

Extension A32 (System)

Operands

coproc
CP Num
Rt
Transfer general-purpose register (load/store)
CRn
Dest CP Reg

Reference

View in Arm A64 ISA Reference ↗ Arm AArch32 ISA

Instruction Forms

Encoding	Instruction		ISA		Bit pattern
0x0E000E10	MCR{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}		A32		cond \| 1110 \| opc1 \| 0 \| CRn \| Rt \| 111 \| coproc<0> \| opc2 \| 1 \| CRm
0xEE000E10	MCR{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}		T32		11101110 \| opc1 \| 0 \| CRn \| Rt \| 111 \| coproc<0> \| opc2 \| 1 \| CRm

Description

Move to System register from general-purpose register or execute a System instruction. This instruction copies the value of a general-purpose register to a System register, or executes a System instruction. The System register and System instruction descriptions identify valid encodings for this instruction. Other encodings are undefined. For more information see About the AArch32 System register interface and General behavior of System registers. In an implementation that includes EL2, MCR accesses to System registers can be trapped to Hyp mode, meaning that an attempt to execute an MCR instruction in a Non-secure mode other than Hyp mode, that would be permitted in the absence of the Hyp trap controls, generates a Hyp Trap exception. For more information, see EL2 configurable instruction enables, disables, and traps. Because of the range of possible traps to Hyp mode, the MCR pseudocode does not show these possible traps.

Operation

if ConditionPassed() then
    EncodingSpecificOperations();
    AArch32.SysRegWrite(cp, ThisInstr(), t);

mcr