AMCNTENSET0_EL0, Activity Monitors Count Enable Set Register 0

The AMCNTENSET0_EL0 characteristics are:

Purpose

Enable control bits for the architected activity monitors event counters, AMEVCNTR0<n>_EL0.

Configuration

AArch64 System register AMCNTENSET0_EL0 bits [31:0] are architecturally mapped to AArch32 System register AMCNTENSET0[31:0] .

AArch64 System register AMCNTENSET0_EL0 bits [31:0] are architecturally mapped to External register AMCNTENSET0[31:0] .

This register is present only when AMUv1 is implemented. Otherwise, direct accesses to AMCNTENSET0_EL0 are UNDEFINED.

Some or all RW fields of this register have defined reset values. These apply only if the PE resets into an Exception level that is using AArch64. Otherwise, RW fields in this register reset to architecturally UNKNOWN values.

Attributes

AMCNTENSET0_EL0 is a 64-bit register.

Field descriptions

The AMCNTENSET0_EL0 bit assignments are:

6362616059585756555453525150494847464544434241403938373635343332
RES0
P<n>, bit [n]
313029282726252423222120191817161514131211109876543210

Bits [63:32]

Reserved, RES0.

P<n>, bit [n], for n = 0 to 31

Activity monitor event counter enable bit for AMEVCNTR0<n>_EL0.

Bits [31:N] are RAZ/WI. N is the value in AMCGCR_EL0.CG0NC.

Possible values of each bit are:

P<n>Meaning
0b0

When read, means that AMEVCNTR0<n>_EL0 is disabled. When written, has no effect.

0b1

When read, means that AMEVCNTR0<n>_EL0 is enabled. When written, enables AMEVCNTR0<n>_EL0.

On a Cold reset, this field resets to 0.

Accessing the AMCNTENSET0_EL0

Accesses to this register use the following encodings:

MRS <Xt>, AMCNTENSET0_EL0

op0op1CRnCRmop2
0b110b0110b11010b00100b101

if PSTATE.EL == EL0 then if !ELUsingAArch32(EL1) && AMUSERENR_EL0.EN == '0' then if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && !ELUsingAArch32(EL2) && CPTR_EL2.TAM == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && CPTR_EL3.TAM == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else return AMCNTENSET0_EL0; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && CPTR_EL2.TAM == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && CPTR_EL3.TAM == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else return AMCNTENSET0_EL0; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && !ELUsingAArch32(EL3) && CPTR_EL3.TAM == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else return AMCNTENSET0_EL0; elsif PSTATE.EL == EL3 then return AMCNTENSET0_EL0;

MSR AMCNTENSET0_EL0, <Xt>

op0op1CRnCRmop2
0b110b0110b11010b00100b101

if IsHighestEL(PSTATE.EL) then AMCNTENSET0_EL0 = X[t]; else UNDEFINED;




27/03/2019 21:59; e5e4db499bf9867a4b93324c4dbac985d3da9376

Copyright © 2010-2019 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.