Holds the timer value for the EL1 virtual timer.
AArch64 System register CNTV_TVAL_EL0 bits [31:0] are architecturally mapped to AArch32 System register CNTV_TVAL[31:0].
CNTV_TVAL_EL0 is a 64-bit register.
| 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 |
| 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 |
| RES0 | |||||||||||||||||||||||||||||||
| TimerValue | |||||||||||||||||||||||||||||||
Reserved, RES0.
The TimerValue view of the EL1 virtual timer.
On a read of this register:
On a write of this register, CNTV_CVAL_EL0 is set to (CNTVCT_EL0 + TimerValue), where TimerValue is treated as a signed 32-bit integer.
When CNTV_CTL_EL0.ENABLE is 1, the timer condition is met when (CNTVCT_EL0 - CNTV_CVAL_EL0) is greater than or equal to zero. This means that TimerValue acts like a 32-bit downcounter timer. When the timer condition is met:
When CNTV_CTL_EL0.ENABLE is 0, the timer condition is not met, but CNTVCT_EL0 continues to count, so the TimerValue view appears to continue to count down.
The reset behavior of this field is:
When the Effective value of HCR_EL2.E2H is 1, without explicit synchronization, access from EL3 using the mnemonic CNTV_TVAL_EL0 or CNTV_TVAL_EL02 are not guaranteed to be ordered with respect to accesses using the other mnemonic.
Accesses to this register use the following encodings in the System register encoding space:
MRS <Xt>, CNTV_TVAL_EL0
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b011 | 0b1110 | 0b0011 | 0b000 |
if PSTATE.EL == EL0 then if !ELIsInHost(EL0) && CNTKCTL_EL1.EL0VTEN == '0' then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif ELIsInHost(EL0) && CNTHCTL_EL2.EL0VTEN == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && !ELIsInHost(EL0) && CNTHCTL_EL2.EL1TVT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif ELIsInHost(EL0) && SCR_EL3.NS == '0' && IsFeatureImplemented(FEAT_SEL2) then if CNTHVS_CTL_EL2.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTHVS_CVAL_EL2 - PhysicalCountInt(); elsif ELIsInHost(EL0) && SCR_EL3.NS == '1' then if CNTHV_CTL_EL2.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTHV_CVAL_EL2 - PhysicalCountInt(); elsif HaveEL(EL2) && (!EL2Enabled() || !ELIsInHost(EL0)) then if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - (PhysicalCountInt() - CNTVOFF_EL2); else if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - PhysicalCountInt(); elsif PSTATE.EL == EL1 then if EL2Enabled() && CNTHCTL_EL2.EL1TVT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL2) then if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - (PhysicalCountInt() - CNTVOFF_EL2); else if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - PhysicalCountInt(); elsif PSTATE.EL == EL2 then if ELIsInHost(EL2) && SCR_EL3.NS == '0' && IsFeatureImplemented(FEAT_SEL2) then if CNTHVS_CTL_EL2.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTHVS_CVAL_EL2 - PhysicalCountInt(); elsif ELIsInHost(EL2) && SCR_EL3.NS == '1' then if CNTHV_CTL_EL2.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTHV_CVAL_EL2 - PhysicalCountInt(); elsif !ELIsInHost(EL2) then if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - (PhysicalCountInt() - CNTVOFF_EL2); else if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - PhysicalCountInt(); elsif PSTATE.EL == EL3 then if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; elsif HaveEL(EL2) && !ELUsingAArch32(EL2) then X[t, 64] = CNTV_CVAL_EL0 - (PhysicalCountInt() - CNTVOFF_EL2); elsif HaveEL(EL2) && ELUsingAArch32(EL2) then X[t, 64] = CNTV_CVAL_EL0 - (PhysicalCountInt() - CNTVOFF); else X[t, 64] = CNTV_CVAL_EL0 - PhysicalCountInt();
MSR CNTV_TVAL_EL0, <Xt>
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b011 | 0b1110 | 0b0011 | 0b000 |
if PSTATE.EL == EL0 then if !ELIsInHost(EL0) && CNTKCTL_EL1.EL0VTEN == '0' then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif ELIsInHost(EL0) && CNTHCTL_EL2.EL0VTEN == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && !ELIsInHost(EL0) && CNTHCTL_EL2.EL1TVT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif ELIsInHost(EL0) && SCR_EL3.NS == '0' && IsFeatureImplemented(FEAT_SEL2) then CNTHVS_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif ELIsInHost(EL0) && SCR_EL3.NS == '1' then CNTHV_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif HaveEL(EL2) && (!EL2Enabled() || !ELIsInHost(EL0)) then CNTV_CVAL_EL0 = (SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt()) - CNTVOFF_EL2; else CNTV_CVAL_EL0 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif PSTATE.EL == EL1 then if EL2Enabled() && CNTHCTL_EL2.EL1TVT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL2) then CNTV_CVAL_EL0 = (SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt()) - CNTVOFF_EL2; else CNTV_CVAL_EL0 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif PSTATE.EL == EL2 then if ELIsInHost(EL2) && SCR_EL3.NS == '0' && IsFeatureImplemented(FEAT_SEL2) then CNTHVS_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif ELIsInHost(EL2) && SCR_EL3.NS == '1' then CNTHV_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif !ELIsInHost(EL2) then CNTV_CVAL_EL0 = (SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt()) - CNTVOFF_EL2; else CNTV_CVAL_EL0 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif PSTATE.EL == EL3 then if HaveEL(EL2) && !ELUsingAArch32(EL2) then CNTV_CVAL_EL0 = (SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt()) - CNTVOFF_EL2; elsif HaveEL(EL2) && ELUsingAArch32(EL2) then CNTV_CVAL_EL0 = (SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt()) - CNTVOFF; else CNTV_CVAL_EL0 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt();
MRS <Xt>, CNTV_TVAL_EL02
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b101 | 0b1110 | 0b0011 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if ELIsInHost(EL2) then if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - (PhysicalCountInt() - CNTVOFF_EL2); else UNDEFINED; elsif PSTATE.EL == EL3 then if ELIsInHost(EL2) then if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - (PhysicalCountInt() - CNTVOFF_EL2); else UNDEFINED;
MSR CNTV_TVAL_EL02, <Xt>
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b101 | 0b1110 | 0b0011 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if ELIsInHost(EL2) then CNTV_CVAL_EL0 = (SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt()) - CNTVOFF_EL2; else UNDEFINED; elsif PSTATE.EL == EL3 then if ELIsInHost(EL2) then CNTV_CVAL_EL0 = (SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt()) - CNTVOFF_EL2; else UNDEFINED;