CNTHPS_TVAL_EL2, Counter-timer Secure Physical Timer TimerValue register (EL2)
The CNTHPS_TVAL_EL2 characteristics are:
Purpose
Holds the timer value for the Secure EL2 physical timer.
Configuration
AArch64 System register CNTHPS_TVAL_EL2 bits [31:0] are architecturally mapped to AArch32 System register CNTHPS_TVAL[31:0] .
This register is present only when EL2 is implemented and FEAT_SEL2 is implemented. Otherwise, direct accesses to CNTHPS_TVAL_EL2 are UNDEFINED.
Attributes
CNTHPS_TVAL_EL2 is a 64-bit register.
Field descriptions
The CNTHPS_TVAL_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 |
RES0 | |||||||||||||||||||||||||||||||
TimerValue | |||||||||||||||||||||||||||||||
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 [63:32]
Reserved, RES0.
TimerValue, bits [31:0]
The TimerValue view of the EL2 physical timer.
On a read of this register:
- If CNTHPS_CTL_EL2.ENABLE is 0, the value returned is UNKNOWN.
- If CNTHPS_CTL_EL2.ENABLE is 1, the value returned is (CNTHPS_CVAL_EL2 - CNTPCT_EL0).
On a write of this register, CNTHPS_CVAL_EL2 is set to (CNTPCT_EL0 + TimerValue), where TimerValue is treated as a signed 32-bit integer.
When CNTHPS_CTL_EL2.ENABLE is 1, the timer condition is met when (CNTPCT_EL0 - CNTHPS_CVAL_EL2) is greater than or equal to zero. This means that TimerValue acts like a 32-bit downcounter 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, so the TimerValue view appears to continue to count down.
This field resets to an architecturally UNKNOWN value.
Accessing the CNTHPS_TVAL_EL2
Accesses to this register use the following encodings:
MRS <Xt>, CNTHPS_TVAL_EL2
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b11 | 0b100 | 0b1110 | 0b0101 | 0b000 |
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_TVAL_EL2; elsif PSTATE.EL == EL3 then if SCR_EL3.EEL2 == '0' then UNDEFINED; else return CNTHPS_TVAL_EL2;
MSR CNTHPS_TVAL_EL2, <Xt>
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b11 | 0b100 | 0b1110 | 0b0101 | 0b000 |
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_TVAL_EL2 = X[t]; elsif PSTATE.EL == EL3 then if SCR_EL3.EEL2 == '0' then UNDEFINED; else CNTHPS_TVAL_EL2 = X[t];
MRS <Xt>, CNTP_TVAL_EL0
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b11 | 0b011 | 0b1110 | 0b0010 | 0b000 |
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_TVAL_EL2; elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && SCR_EL3.NS == '1' then return CNTHP_TVAL_EL2; else return CNTP_TVAL_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); else return CNTP_TVAL_EL0; elsif PSTATE.EL == EL2 then if HCR_EL2.E2H == '1' && SCR_EL3.NS == '0' && IsFeatureImplemented("FEAT_SEL2") then return CNTHPS_TVAL_EL2; elsif HCR_EL2.E2H == '1' && SCR_EL3.NS == '1' then return CNTHP_TVAL_EL2; else return CNTP_TVAL_EL0; elsif PSTATE.EL == EL3 then return CNTP_TVAL_EL0;
MSR CNTP_TVAL_EL0, <Xt>
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b11 | 0b011 | 0b1110 | 0b0010 | 0b000 |
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_TVAL_EL2 = X[t]; elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && SCR_EL3.NS == '1' then CNTHP_TVAL_EL2 = X[t]; else CNTP_TVAL_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); else CNTP_TVAL_EL0 = X[t]; elsif PSTATE.EL == EL2 then if HCR_EL2.E2H == '1' && SCR_EL3.NS == '0' && IsFeatureImplemented("FEAT_SEL2") then CNTHPS_TVAL_EL2 = X[t]; elsif HCR_EL2.E2H == '1' && SCR_EL3.NS == '1' then CNTHP_TVAL_EL2 = X[t]; else CNTP_TVAL_EL0 = X[t]; elsif PSTATE.EL == EL3 then CNTP_TVAL_EL0 = X[t];