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# CurrentEL, Current Exception Level

The CurrentEL characteristics are:

## Purpose

Holds the current Exception level.

## Configuration

There are no configuration notes.

## Attributes

CurrentEL is a 64-bit register.

## Field descriptions

63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 38 | 37 | 36 | 35 | 34 | 33 | 32
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
RES0
RES0 | EL | RES0

#### Bits [63:4]

Reserved, RES0.

#### EL, bits [3:2]

Current Exception level.

EL | Meaning
--- | ---
0b00 | EL0.
0b01 | EL1.
0b10 | EL2.
0b11 | EL3.

When the Effective value of HCR_EL2.NV is 1, EL1 read accesses to the CurrentEL register return the value of 0b10 in this field.

The reset behavior of this field is:

- On a Warm reset:
  - When the highest implemented Exception level is EL1, this field resets to 1.
  - When the highest implemented Exception level is EL2, this field resets to 2.
  - Otherwise, this field resets to 3.

#### Bits [1:0]

Reserved, RES0.

## Accessing CurrentEL

Accesses to this register use the following encodings in the System register encoding space:

#### MRS <Xt>, CurrentEL

op0 | op1 | CRn | CRm | op2
--- | --- | --- | --- | ---
0b11 | 0b000 | 0b0100 | 0b0010 | 0b010

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() IN {'xx1'} then X[t, 64] = Zeros(60):'10':Zeros(2); else X[t, 64] = Zeros(60):PSTATE.EL:Zeros(2); elsif PSTATE.EL == EL2 then X[t, 64] = Zeros(60):PSTATE.EL:Zeros(2); elsif PSTATE.EL == EL3 then X[t, 64] = Zeros(60):PSTATE.EL:Zeros(2);

AArch32 Registers | AArch64 Registers | AArch32 Instructions | AArch64 Instructions | Index by Encoding | External Registers | External Registers by Offset | Registers by Functional Group | Proprietary Notice

26/03/2024 09:49; 67c0ae5282a7629ba0ea0ba7267b43cd4f7939f6

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