Holds the compare value for the virtual timer.
AArch64 System register CNTV_CVAL_EL0 bits [63:0] are architecturally mapped to AArch32 System register CNTV_CVAL[63:0].
CNTV_CVAL_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 |
| CompareValue | |||||||||||||||||||||||||||||||
| CompareValue | |||||||||||||||||||||||||||||||
Holds the EL1 virtual timer CompareValue.
When CNTV_CTL_EL0.ENABLE is 1, the timer condition is met when (CNTVCT_EL0 - 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:
When CNTV_CTL_EL0.ENABLE is 0, the timer condition is not met, but CNTVCT_EL0 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:
When the Effective value of HCR_EL2.E2H is 1, without explicit synchronization, access from EL3 using the mnemonic CNTV_CVAL_EL0 or CNTV_CVAL_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_CVAL_EL0
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b011 | 0b1110 | 0b0011 | 0b010 |
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 X[t, 64] = CNTHVS_CVAL_EL2; elsif ELIsInHost(EL0) && SCR_EL3.NS == '1' then X[t, 64] = CNTHV_CVAL_EL2; else X[t, 64] = CNTV_CVAL_EL0; elsif PSTATE.EL == EL1 then if EL2Enabled() && CNTHCTL_EL2.EL1TVT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EffectiveHCR_EL2_NVx() == '111' then X[t, 64] = NVMem[0x168]; else X[t, 64] = CNTV_CVAL_EL0; elsif PSTATE.EL == EL2 then if ELIsInHost(EL2) && SCR_EL3.NS == '0' && IsFeatureImplemented(FEAT_SEL2) then X[t, 64] = CNTHVS_CVAL_EL2; elsif ELIsInHost(EL2) && SCR_EL3.NS == '1' then X[t, 64] = CNTHV_CVAL_EL2; else X[t, 64] = CNTV_CVAL_EL0; elsif PSTATE.EL == EL3 then X[t, 64] = CNTV_CVAL_EL0;
MSR CNTV_CVAL_EL0, <Xt>
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b011 | 0b1110 | 0b0011 | 0b010 |
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 = X[t, 64]; elsif ELIsInHost(EL0) && SCR_EL3.NS == '1' then CNTHV_CVAL_EL2 = X[t, 64]; else CNTV_CVAL_EL0 = X[t, 64]; elsif PSTATE.EL == EL1 then if EL2Enabled() && CNTHCTL_EL2.EL1TVT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EffectiveHCR_EL2_NVx() == '111' then NVMem[0x168] = X[t, 64]; else CNTV_CVAL_EL0 = X[t, 64]; elsif PSTATE.EL == EL2 then if ELIsInHost(EL2) && SCR_EL3.NS == '0' && IsFeatureImplemented(FEAT_SEL2) then CNTHVS_CVAL_EL2 = X[t, 64]; elsif ELIsInHost(EL2) && SCR_EL3.NS == '1' then CNTHV_CVAL_EL2 = X[t, 64]; else CNTV_CVAL_EL0 = X[t, 64]; elsif PSTATE.EL == EL3 then CNTV_CVAL_EL0 = X[t, 64];
MRS <Xt>, CNTV_CVAL_EL02
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b101 | 0b1110 | 0b0011 | 0b010 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() == '101' then if EL2Enabled() && !ELIsInHost(EL0) && CNTHCTL_EL2.EL1NVVCT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else X[t, 64] = NVMem[0x168]; elsif EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if ELIsInHost(EL2) then X[t, 64] = CNTV_CVAL_EL0; else UNDEFINED; elsif PSTATE.EL == EL3 then if ELIsInHost(EL2) then X[t, 64] = CNTV_CVAL_EL0; else UNDEFINED;
MSR CNTV_CVAL_EL02, <Xt>
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b101 | 0b1110 | 0b0011 | 0b010 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() == '101' then if EL2Enabled() && !ELIsInHost(EL0) && CNTHCTL_EL2.EL1NVVCT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else NVMem[0x168] = X[t, 64]; elsif EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if ELIsInHost(EL2) then CNTV_CVAL_EL0 = X[t, 64]; else UNDEFINED; elsif PSTATE.EL == EL3 then if ELIsInHost(EL2) then CNTV_CVAL_EL0 = X[t, 64]; else UNDEFINED;