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TRFCR_EL1, Trace Filter Control Register (EL1)

The TRFCR_EL1 characteristics are:

Purpose

Provides EL1 controls for Trace.

Configuration

AArch64 System register TRFCR_EL1 bits [31:0] are architecturally mapped to AArch32 System register TRFCR[31:0] .

This register is present only when FEAT_TRF is implemented. Otherwise, direct accesses to TRFCR_EL1 are UNDEFINED.

Attributes

TRFCR_EL1 is a 64-bit register.

Field descriptions

The TRFCR_EL1 bit assignments are:

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
RES0
RES0																									TS		RES0			E1TRE	E0TRE
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

Bits [63:7]

Reserved, RES0.

TS, bits [6:5]

Timestamp Control. Controls which timebase is used for trace timestamps.

TS	Meaning	Applies when
0b01	Virtual timestamp. The traced timestamp is the physical counter value minus the value of CNTVOFF_EL2.
0b10	Guest physical timestamp. The traced timestamp is the physical counter value minus a physical offset. If any of the following are true, the physical offset is zero, otherwise the physical offset is the value of CNTPOFF_EL2: SCR_EL3.ECVEn == 0b0. CNTHCTL_EL2.ECV == 0b0.	When FEAT_ECV is implemented
0b11	Physical timestamp. The traced timestamp is the physical counter value.

Meaning

Applies when

0b01

Virtual timestamp. The traced timestamp is the physical counter value minus the value of CNTVOFF_EL2.

0b10

Guest physical timestamp. The traced timestamp is the physical counter value minus a physical offset. If any of the following are true, the physical offset is zero, otherwise the physical offset is the value of CNTPOFF_EL2:

SCR_EL3.ECVEn == 0b0.
CNTHCTL_EL2.ECV == 0b0.

When FEAT_ECV is implemented

0b11

Physical timestamp. The traced timestamp is the physical counter value.

All other values are reserved.

This field is ignored by the PE when any of the following are true:

EL2 is implemented and TRFCR_EL2.TS != 0b00.
SelfHostedTraceEnabled() == FALSE.

On a Warm reset, this field resets to an architecturally UNKNOWN value.

Bits [4:2]

Reserved, RES0.

E1TRE, bit [1]

EL1 Trace Enable.

E1TRE	Meaning
0b0	Trace is prohibited at EL1.
0b1	Trace is allowed at EL1.

This field is ignored if SelfHostedTraceEnabled() == FALSE.

On a Warm reset, this field resets to 0.

E0TRE, bit [0]

EL0 Trace Enable.

E0TRE	Meaning
0b0	Trace is prohibited at EL0.
0b1	Trace is allowed at EL0.

This field is ignored if any of the following are true:

SelfHostedTraceEnabled() == FALSE.
EL2 is implemented and enabled in the current Security state and HCR_EL2.TGE == 1.

On a Warm reset, this field resets to 0.

Accessing the TRFCR_EL1

Accesses to this register use the following encodings:

MRS <Xt>, TRFCR_EL1

op0	op1	CRn	CRm	op2
0b11	0b000	0b0001	0b0010	0b001

if PSTATE.EL == EL0 then
    UNDEFINED;
elsif PSTATE.EL == EL1 then
    if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && MDCR_EL3.TTRF == '1' then
        UNDEFINED;
    elsif EL2Enabled() && MDCR_EL2.TTRF == '1' then
        AArch64.SystemAccessTrap(EL2, 0x18);
    elsif HaveEL(EL3) && MDCR_EL3.TTRF == '1' then
        if Halted() && EDSCR.SDD == '1' then
            UNDEFINED;
        else
            AArch64.SystemAccessTrap(EL3, 0x18);
    elsif EL2Enabled() && HCR_EL2.<NV2,NV1,NV> == '111' then
        return NVMem[0x880];
    else
        return TRFCR_EL1;
elsif PSTATE.EL == EL2 then
    if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && MDCR_EL3.TTRF == '1' then
        UNDEFINED;
    elsif HaveEL(EL3) && MDCR_EL3.TTRF == '1' then
        if Halted() && EDSCR.SDD == '1' then
            UNDEFINED;
        else
            AArch64.SystemAccessTrap(EL3, 0x18);
    elsif HCR_EL2.E2H == '1' then
        return TRFCR_EL2;
    else
        return TRFCR_EL1;
elsif PSTATE.EL == EL3 then
    return TRFCR_EL1;

MSR TRFCR_EL1, <Xt>

op0	op1	CRn	CRm	op2
0b11	0b000	0b0001	0b0010	0b001

if PSTATE.EL == EL0 then
    UNDEFINED;
elsif PSTATE.EL == EL1 then
    if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && MDCR_EL3.TTRF == '1' then
        UNDEFINED;
    elsif EL2Enabled() && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGWTR_EL2.TRFCR_EL1 == '1' then
        AArch64.SystemAccessTrap(EL2, 0x18);
    elsif EL2Enabled() && MDCR_EL2.TTRF == '1' then
        AArch64.SystemAccessTrap(EL2, 0x18);
    elsif HaveEL(EL3) && MDCR_EL3.TTRF == '1' then
        if Halted() && EDSCR.SDD == '1' then
            UNDEFINED;
        else
            AArch64.SystemAccessTrap(EL3, 0x18);
    elsif EL2Enabled() && HCR_EL2.<NV2,NV1,NV> == '111' then
        NVMem[0x880] = X[t];
    else
        TRFCR_EL1 = X[t];
elsif PSTATE.EL == EL2 then
    if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && MDCR_EL3.TTRF == '1' then
        UNDEFINED;
    elsif HaveEL(EL3) && MDCR_EL3.TTRF == '1' then
        if Halted() && EDSCR.SDD == '1' then
            UNDEFINED;
        else
            AArch64.SystemAccessTrap(EL3, 0x18);
    elsif HCR_EL2.E2H == '1' then
        TRFCR_EL2 = X[t];
    else
        TRFCR_EL1 = X[t];
elsif PSTATE.EL == EL3 then
    TRFCR_EL1 = X[t];

MRS <Xt>, TRFCR_EL12

op0	op1	CRn	CRm	op2
0b11	0b101	0b0001	0b0010	0b001

if PSTATE.EL == EL0 then
    UNDEFINED;
elsif PSTATE.EL == EL1 then
    if EL2Enabled() && HCR_EL2.<NV2,NV1,NV> == '101' then
        return NVMem[0x880];
    elsif EL2Enabled() && HCR_EL2.NV == '1' then
        AArch64.SystemAccessTrap(EL2, 0x18);
    else
        UNDEFINED;
elsif PSTATE.EL == EL2 then
    if HCR_EL2.E2H == '1' then
        if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && MDCR_EL3.TTRF == '1' then
            UNDEFINED;
        elsif HaveEL(EL3) && MDCR_EL3.TTRF == '1' then
            if Halted() && EDSCR.SDD == '1' then
                UNDEFINED;
            else
                AArch64.SystemAccessTrap(EL3, 0x18);
        else
            return TRFCR_EL1;
    else
        UNDEFINED;
elsif PSTATE.EL == EL3 then
    if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.E2H == '1' then
        return TRFCR_EL1;
    else
        UNDEFINED;

MSR TRFCR_EL12, <Xt>

op0	op1	CRn	CRm	op2
0b11	0b101	0b0001	0b0010	0b001

if PSTATE.EL == EL0 then
    UNDEFINED;
elsif PSTATE.EL == EL1 then
    if EL2Enabled() && HCR_EL2.<NV2,NV1,NV> == '101' then
        NVMem[0x880] = X[t];
    elsif EL2Enabled() && HCR_EL2.NV == '1' then
        AArch64.SystemAccessTrap(EL2, 0x18);
    else
        UNDEFINED;
elsif PSTATE.EL == EL2 then
    if HCR_EL2.E2H == '1' then
        if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && MDCR_EL3.TTRF == '1' then
            UNDEFINED;
        elsif HaveEL(EL3) && MDCR_EL3.TTRF == '1' then
            if Halted() && EDSCR.SDD == '1' then
                UNDEFINED;
            else
                AArch64.SystemAccessTrap(EL3, 0x18);
        else
            TRFCR_EL1 = X[t];
    else
        UNDEFINED;
elsif PSTATE.EL == EL3 then
    if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.E2H == '1' then
        TRFCR_EL1 = X[t];
    else
        UNDEFINED;

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