CNTHPS_CVAL_EL2, Counter-timer Secure Physical Timer CompareValue register (EL2)
The CNTHPS_CVAL_EL2 characteristics are:
Purpose
Holds the compare value for the Secure EL2 physical timer.
Configuration
AArch64 System register CNTHPS_CVAL_EL2 bits [31:0] are architecturally mapped to AArch32 System register CNTHPS_CVAL[31:0] .
This register is present only when EL2 is implemented and FEAT_SEL2 is implemented. Otherwise, direct accesses to CNTHPS_CVAL_EL2 are UNDEFINED.
Attributes
CNTHPS_CVAL_EL2 is a 64-bit register.
Field descriptions
The CNTHPS_CVAL_EL2 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 |
| CompareValue | |||||||||||||||||||||||||||||||
| CompareValue | |||||||||||||||||||||||||||||||
| 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, bits [63:0]
Holds the EL2 physical timer CompareValue.
When CNTHPS_CTL_EL2.ENABLE is 1, the timer condition is met when (CNTPCT_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:
- CNTHPS_CTL_EL2.ISTATUS is set to 1.
- If CNTHPS_CTL_EL2.IMASK is 0, an interrupt is generated.
When CNTHPS_CTL_EL2.ENABLE is 0, the timer condition is not met, but CNTPCT_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.
On a Warm reset, this field resets to an architecturally UNKNOWN value.
Accessing the CNTHPS_CVAL_EL2
Accesses to this register use the following encodings:
MRS <Xt>, CNTHPS_CVAL_EL2
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b100 | 0b1110 | 0b0101 | 0b010 |
if PSTATE.EL == EL0 then
UNDEFINED;
elsif PSTATE.EL == EL1 then
if HaveEL(EL3) && SCR_EL3.NS == '1' then
UNDEFINED;
elsif EL2Enabled() && HCR_EL2.NV == '1' then
AArch64.SystemAccessTrap(EL2, 0x18);
else
UNDEFINED;
elsif PSTATE.EL == EL2 then
if HaveEL(EL3) && SCR_EL3.NS == '1' then
UNDEFINED;
else
return CNTHPS_CVAL_EL2;
elsif PSTATE.EL == EL3 then
if SCR_EL3.EEL2 == '0' then
UNDEFINED;
else
return CNTHPS_CVAL_EL2;
MSR CNTHPS_CVAL_EL2, <Xt>
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b100 | 0b1110 | 0b0101 | 0b010 |
if PSTATE.EL == EL0 then
UNDEFINED;
elsif PSTATE.EL == EL1 then
if HaveEL(EL3) && SCR_EL3.NS == '1' then
UNDEFINED;
elsif EL2Enabled() && HCR_EL2.NV == '1' then
AArch64.SystemAccessTrap(EL2, 0x18);
else
UNDEFINED;
elsif PSTATE.EL == EL2 then
if HaveEL(EL3) && SCR_EL3.NS == '1' then
UNDEFINED;
else
CNTHPS_CVAL_EL2 = X[t];
elsif PSTATE.EL == EL3 then
if SCR_EL3.EEL2 == '0' then
UNDEFINED;
else
CNTHPS_CVAL_EL2 = X[t];
MRS <Xt>, CNTP_CVAL_EL0
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b011 | 0b1110 | 0b0010 | 0b010 |
if PSTATE.EL == EL0 then
if !(EL2Enabled() && HCR_EL2.<E2H,TGE> == '11') && CNTKCTL_EL1.EL0PTEN == '0' then
if EL2Enabled() && HCR_EL2.TGE == '1' then
AArch64.SystemAccessTrap(EL2, 0x18);
else
AArch64.SystemAccessTrap(EL1, 0x18);
elsif EL2Enabled() && HCR_EL2.E2H == '0' && CNTHCTL_EL2.EL1PCEN == '0' then
AArch64.SystemAccessTrap(EL2, 0x18);
elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '10' && CNTHCTL_EL2.EL1PTEN == '0' then
AArch64.SystemAccessTrap(EL2, 0x18);
elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && CNTHCTL_EL2.EL0PTEN == '0' then
AArch64.SystemAccessTrap(EL2, 0x18);
elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && SCR_EL3.NS == '0' && IsFeatureImplemented(FEAT_SEL2) then
return CNTHPS_CVAL_EL2;
elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && SCR_EL3.NS == '1' then
return CNTHP_CVAL_EL2;
else
return CNTP_CVAL_EL0;
elsif PSTATE.EL == EL1 then
if EL2Enabled() && HCR_EL2.E2H == '0' && CNTHCTL_EL2.EL1PCEN == '0' then
AArch64.SystemAccessTrap(EL2, 0x18);
elsif EL2Enabled() && HCR_EL2.E2H == '1' && CNTHCTL_EL2.EL1PTEN == '0' then
AArch64.SystemAccessTrap(EL2, 0x18);
elsif EL2Enabled() && HCR_EL2.<NV2,NV1,NV> == '111' then
return NVMem[0x178];
else
return CNTP_CVAL_EL0;
elsif PSTATE.EL == EL2 then
if HCR_EL2.E2H == '1' && SCR_EL3.NS == '0' && IsFeatureImplemented(FEAT_SEL2) then
return CNTHPS_CVAL_EL2;
elsif HCR_EL2.E2H == '1' && SCR_EL3.NS == '1' then
return CNTHP_CVAL_EL2;
else
return CNTP_CVAL_EL0;
elsif PSTATE.EL == EL3 then
return CNTP_CVAL_EL0;
MSR CNTP_CVAL_EL0, <Xt>
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b011 | 0b1110 | 0b0010 | 0b010 |
if PSTATE.EL == EL0 then
if !(EL2Enabled() && HCR_EL2.<E2H,TGE> == '11') && CNTKCTL_EL1.EL0PTEN == '0' then
if EL2Enabled() && HCR_EL2.TGE == '1' then
AArch64.SystemAccessTrap(EL2, 0x18);
else
AArch64.SystemAccessTrap(EL1, 0x18);
elsif EL2Enabled() && HCR_EL2.E2H == '0' && CNTHCTL_EL2.EL1PCEN == '0' then
AArch64.SystemAccessTrap(EL2, 0x18);
elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '10' && CNTHCTL_EL2.EL1PTEN == '0' then
AArch64.SystemAccessTrap(EL2, 0x18);
elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && CNTHCTL_EL2.EL0PTEN == '0' then
AArch64.SystemAccessTrap(EL2, 0x18);
elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && SCR_EL3.NS == '0' && IsFeatureImplemented(FEAT_SEL2) then
CNTHPS_CVAL_EL2 = X[t];
elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && SCR_EL3.NS == '1' then
CNTHP_CVAL_EL2 = X[t];
else
CNTP_CVAL_EL0 = X[t];
elsif PSTATE.EL == EL1 then
if EL2Enabled() && HCR_EL2.E2H == '0' && CNTHCTL_EL2.EL1PCEN == '0' then
AArch64.SystemAccessTrap(EL2, 0x18);
elsif EL2Enabled() && HCR_EL2.E2H == '1' && CNTHCTL_EL2.EL1PTEN == '0' then
AArch64.SystemAccessTrap(EL2, 0x18);
elsif EL2Enabled() && HCR_EL2.<NV2,NV1,NV> == '111' then
NVMem[0x178] = X[t];
else
CNTP_CVAL_EL0 = X[t];
elsif PSTATE.EL == EL2 then
if HCR_EL2.E2H == '1' && SCR_EL3.NS == '0' && IsFeatureImplemented(FEAT_SEL2) then
CNTHPS_CVAL_EL2 = X[t];
elsif HCR_EL2.E2H == '1' && SCR_EL3.NS == '1' then
CNTHP_CVAL_EL2 = X[t];
else
CNTP_CVAL_EL0 = X[t];
elsif PSTATE.EL == EL3 then
CNTP_CVAL_EL0 = X[t];