CNTV_CVAL

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CNTV_CVAL, Counter-timer Virtual Timer CompareValue register

Purpose

Configuration

AArch32 System register CNTV_CVAL bits [63:0] are architecturally mapped to AArch64 System register CNTV_CVAL_EL0[63:0].

This register is present only when FEAT_AA32 is implemented. Otherwise, direct accesses to CNTV_CVAL are UNDEFINED.

Attributes

Field descriptions

CompareValue, bits [63:0]

Holds the EL1 virtual timer CompareValue.

When CNTV_CTL.ENABLE is 1, the timer condition is met when (CNTVCT - CompareValue) is greater than or equal to zero. This means that CompareValue acts like a 64-bit upcounter timer. When the timer condition is met:

CNTV_CTL.ISTATUS is set to 1.
If CNTV_CTL.IMASK is 0, an interrupt is generated.

When CNTV_CTL.ENABLE is 0, the timer condition is not met, but CNTVCT continues to count.

If the Generic counter is implemented at a size less than 64 bits, then this field is permitted to be implemented at the same width as the counter, and the upper bits are RES0.

The value of this field is treated as zero-extended in all counter calculations.

The reset behavior of this field is:

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

Accessing CNTV_CVAL

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

MRRC{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <Rt2>, <CRm>

coproc	CRm	opc1
0b1111	0b1110	0b0011

if !IsFeatureImplemented(FEAT_AA32) then Undefined(); elsif PSTATE.EL == EL0 then if IsFeatureImplemented(FEAT_AA64EL1) && !ELUsingAArch32(EL1) && !ELIsInHost(EL0) && CNTKCTL_EL1().EL0VTEN == '0' then if EL2Enabled() && (IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2)) && HCR_EL2().TGE == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x04); else AArch64_AArch32SystemAccessTrap(EL1, 0x04); end; elsif IsFeatureImplemented(FEAT_AA32EL1) && ELUsingAArch32(EL1) && CNTKCTL().PL0VTEN == '0' then if EL2Enabled() && (IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2)) && HCR_EL2().TGE == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x04); elsif EL2Enabled() && (IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2)) && HCR().TGE == '1' then AArch32_TakeHypTrapException(0x00); else Undefined(); end; elsif ELIsInHost(EL0) && (IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2)) && CNTHCTL_EL2().EL0VTEN == '0' then AArch64_AArch32SystemAccessTrap(EL2, 0x04); elsif EL2Enabled() && (IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2)) && !ELIsInHost(EL0) && IsFeatureImplemented(FEAT_ECV) && CNTHCTL_EL2().EL1TVT == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x04); elsif ELIsInHost(EL0) && IsCurrentSecurityState(SS_Secure) && IsFeatureImplemented(FEAT_SEL2) then R(t, t2) = CNTHVS_CVAL_EL2(); elsif ELIsInHost(EL0) && !IsCurrentSecurityState(SS_Secure) then R(t, t2) = CNTHV_CVAL_EL2(); else R(t, t2) = CNTV_CVAL(); end; elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && IsFeatureImplemented(FEAT_ECV) && CNTHCTL_EL2().EL1TVT == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x04); else R(t, t2) = CNTV_CVAL(); end; elsif PSTATE.EL == EL2 then R(t, t2) = CNTV_CVAL(); elsif PSTATE.EL == EL3 then R(t, t2) = CNTV_CVAL(); end;

MCRR{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <Rt2>, <CRm>

coproc	CRm	opc1
0b1111	0b1110	0b0011

if !IsFeatureImplemented(FEAT_AA32) then Undefined(); elsif PSTATE.EL == EL0 then if IsFeatureImplemented(FEAT_AA64EL1) && !ELUsingAArch32(EL1) && !ELIsInHost(EL0) && CNTKCTL_EL1().EL0VTEN == '0' then if EL2Enabled() && (IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2)) && HCR_EL2().TGE == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x04); else AArch64_AArch32SystemAccessTrap(EL1, 0x04); end; elsif IsFeatureImplemented(FEAT_AA32EL1) && ELUsingAArch32(EL1) && CNTKCTL().PL0VTEN == '0' then if EL2Enabled() && (IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2)) && HCR_EL2().TGE == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x04); elsif EL2Enabled() && (IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2)) && HCR().TGE == '1' then AArch32_TakeHypTrapException(0x00); else Undefined(); end; elsif ELIsInHost(EL0) && (IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2)) && CNTHCTL_EL2().EL0VTEN == '0' then AArch64_AArch32SystemAccessTrap(EL2, 0x04); elsif EL2Enabled() && (IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2)) && !ELIsInHost(EL0) && IsFeatureImplemented(FEAT_ECV) && CNTHCTL_EL2().EL1TVT == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x04); elsif ELIsInHost(EL0) && IsCurrentSecurityState(SS_Secure) && IsFeatureImplemented(FEAT_SEL2) then CNTHVS_CVAL_EL2() = R(t, t2); elsif ELIsInHost(EL0) && !IsCurrentSecurityState(SS_Secure) then CNTHV_CVAL_EL2() = R(t, t2); else CNTV_CVAL() = R(t, t2); end; elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && IsFeatureImplemented(FEAT_ECV) && CNTHCTL_EL2().EL1TVT == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x04); else CNTV_CVAL() = R(t, t2); end; elsif PSTATE.EL == EL2 then CNTV_CVAL() = R(t, t2); elsif PSTATE.EL == EL3 then CNTV_CVAL() = R(t, t2); end;

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CompareValue
CompareValue