AMCGCR_EL0, Activity Monitors Counter Group Configuration Register

The AMCGCR_EL0 characteristics are:

Purpose

Provides information on the number of activity monitor event counters implemented within each counter group.

Configuration

AArch64 System register AMCGCR_EL0 bits [31:0] are architecturally mapped to AArch32 System register AMCGCR[31:0].

AArch64 System register AMCGCR_EL0 bits [31:0] are architecturally mapped to External register AMCGCR[31:0].

This register is present only when FEAT_AMUv1 is implemented. Otherwise, direct accesses to AMCGCR_EL0 are UNDEFINED.

Attributes

AMCGCR_EL0 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
RES0
RES0CG1NCCG0NC

Bits [63:16]

Reserved, RES0.

CG1NC, bits [15:8]

Counter Group 1 Number of Counters. The number of counters in the auxiliary counter group.

In an implementation that includes FEAT_AMUv1, the permitted range of values is 0x0 to 0x10.

This field has an IMPLEMENTATION DEFINED value.

Access to this field is RO.

CG0NC, bits [7:0]

Counter Group 0 Number of Counters. The number of counters in the architected counter group.

Reads as 0x04.

Access to this field is RO.

Accessing AMCGCR_EL0

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

MRS <Xt>, AMCGCR_EL0

op0op1CRnCRmop2
0b110b0110b11010b00100b010

if PSTATE.EL == EL0 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && CPTR_EL3.TAM == '1' then UNDEFINED; elsif AMUSERENR_EL0.EN == '0' then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && CPTR_EL2.TAM == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && CPTR_EL3.TAM == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else return AMCGCR_EL0; elsif PSTATE.EL == EL1 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && CPTR_EL3.TAM == '1' then UNDEFINED; elsif EL2Enabled() && CPTR_EL2.TAM == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && CPTR_EL3.TAM == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else return AMCGCR_EL0; elsif PSTATE.EL == EL2 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && CPTR_EL3.TAM == '1' then UNDEFINED; elsif HaveEL(EL3) && CPTR_EL3.TAM == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else return AMCGCR_EL0; elsif PSTATE.EL == EL3 then return AMCGCR_EL0;


30/09/2021 14:53; 092b4e1bbfbb45a293b198f9330c5f529ead2b0f

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