Provides identification information for the PE, including an implementer code for the device and a device ID number.
AArch32 System register MIDR bits [31:0] are architecturally mapped to AArch64 System register MIDR_EL1[31:0].
AArch32 System register MIDR bits [31:0] are architecturally mapped to External register MIDR_EL1[31:0].
This register is present only when EL1 is capable of using AArch32. Otherwise, direct accesses to MIDR are UNDEFINED.
Some fields of the MIDR are IMPLEMENTATION DEFINED. For more information about the values of these fields for a particular Armv8 implementation, and any implementation-specific significance of these values, see the product documentation.
MIDR is a 32-bit register.
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| Implementer | Variant | Architecture | PartNum | Revision | |||||||||||||||||||||||||||
The Implementer code. This field must hold an implementer code that has been assigned by Arm.
The value of this field is an IMPLEMENTATION DEFINED choice of:
| Implementer | Meaning |
|---|---|
| 0x00 |
Reserved for software use. |
| 0x41 |
Arm Limited. |
| 0x42 |
Broadcom Corporation. |
| 0x43 |
Cavium Inc. |
| 0x44 |
Digital Equipment Corporation. |
| 0x46 |
Fujitsu Ltd. |
| 0x49 |
Infineon Technologies AG. |
| 0x4D |
Motorola or Freescale Semiconductor Inc. |
| 0x4E |
NVIDIA Corporation. |
| 0x50 |
Applied Micro Circuits Corporation. |
| 0x51 |
Qualcomm Inc. |
| 0x56 |
Marvell International Ltd. |
| 0x69 |
Intel Corporation. |
| 0xC0 |
Ampere Computing. |
Arm can assign codes that are not published in this manual. All values not assigned by Arm are reserved and must not be used.
Access to this field is RO.
Variant number. Typically, this field is used to distinguish between different product variants, or major revisions of a product.
This field has an IMPLEMENTATION DEFINED value.
Access to this field is RO.
Architecture version.
The value of this field is an IMPLEMENTATION DEFINED choice of:
| Architecture | Meaning |
|---|---|
| 0b0001 |
Armv4. |
| 0b0010 |
Armv4T. |
| 0b0011 |
Armv5 (obsolete). |
| 0b0100 |
Armv5T. |
| 0b0101 |
Armv5TE. |
| 0b0110 |
Armv5TEJ. |
| 0b0111 |
Armv6. |
| 0b1111 |
Architectural features are individually identified in the ID_* registers. |
All other values are reserved.
Access to this field is RO.
Primary Part Number for the device.
On processors implemented by Arm, if the top four bits of the primary part number are 0x0 or 0x7, the variant and architecture are encoded differently.
This field has an IMPLEMENTATION DEFINED value.
Access to this field is RO.
Revision number for the device.
This field has an IMPLEMENTATION DEFINED value.
Access to this field is RO.
Accesses to this register use the following encodings in the System register encoding space:
MRC{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}
| coproc | opc1 | CRn | CRm | opc2 |
|---|---|---|---|---|
| 0b1111 | 0b000 | 0b0000 | 0b0000 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T0 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T0 == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) then R[t] = VPIDR_EL2<31:0>; elsif EL2Enabled() && ELUsingAArch32(EL2) then R[t] = VPIDR; else R[t] = MIDR; elsif PSTATE.EL == EL2 then R[t] = MIDR; elsif PSTATE.EL == EL3 then R[t] = MIDR;