ACTLR, Auxiliary Control Register

The ACTLR characteristics are:

Purpose

Provides IMPLEMENTATION DEFINED configuration and control options for execution at EL1 and EL0.

Configuration

AArch32 System register ACTLR bits [31:0] are architecturally mapped to AArch64 System register ACTLR_EL1[31:0].

This register is present only when AArch32 is supported at EL0. Otherwise, direct accesses to ACTLR are UNDEFINED.

Some bits might define global configuration settings, and be common to the Secure and Non-secure instances of the register.

Attributes

ACTLR is a 32-bit register.

Field descriptions

313029282726252423222120191817161514131211109876543210
IMPLEMENTATION DEFINED

IMPLEMENTATION DEFINED, bits [31:0]

IMPLEMENTATION DEFINED.

The reset behaviour of this field is:

Accessing ACTLR

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

MRC{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}

coprocopc1CRnCRmopc2
0b11110b0000b00010b00000b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T1 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T1 == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TACR == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.TAC == '1' then AArch32.TakeHypTrapException(0x03); elsif HaveEL(EL3) && ELUsingAArch32(EL3) then return ACTLR_NS; else return ACTLR; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && ELUsingAArch32(EL3) then return ACTLR_NS; else return ACTLR; elsif PSTATE.EL == EL3 then if SCR.NS == '0' then return ACTLR_S; else return ACTLR_NS;

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

coprocopc1CRnCRmopc2
0b11110b0000b00010b00000b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T1 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T1 == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TACR == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.TAC == '1' then AArch32.TakeHypTrapException(0x03); elsif HaveEL(EL3) && ELUsingAArch32(EL3) then ACTLR_NS = R[t]; else ACTLR = R[t]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && ELUsingAArch32(EL3) then ACTLR_NS = R[t]; else ACTLR = R[t]; elsif PSTATE.EL == EL3 then if SCR.NS == '0' then ACTLR_S = R[t]; else ACTLR_NS = R[t];


30/06/2021 15:21; 2a17f7750cfd1ab239f20f6cf29877ba8041794f

Copyright © 2010-2021 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.