The CNTPCT_EL0 characteristics are:
Holds the 64-bit physical count value.
AArch64 System register CNTPCT_EL0 bits [63:0] are architecturally mapped to AArch32 System register CNTPCT[63:0].
All reads to the CNTPCT_EL0 occur in program order relative to reads to CNTPCTSS_EL0 or CNTPCT_EL0.
CNTPCT_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 |
| Physical count value | |||||||||||||||||||||||||||||||
| Physical count value | |||||||||||||||||||||||||||||||
Physical count value.
Reads of CNTPCT_EL0 from EL0 or EL1 return (PhysicalCountInt<63:0> - CNTPOFF_EL2<63:0>) if the access is not trapped, and all of the following are true:
CNTHCTL_EL2.ECV is 1.
HCR_EL2.{E2H, TGE} is not {1, 1}.
Where PhysicalCountInt<63:0> is the physical count returned when CNTPCT_EL0 is read from EL2 or EL3.
The reset behavior of this field is:
Accesses to this register use the following encodings in the System register encoding space:
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b011 | 0b1110 | 0b0000 | 0b001 |
if PSTATE.EL == EL0 then if !(EL2Enabled() && HCR_EL2.<E2H,TGE> == '11') && CNTKCTL_EL1.EL0PCTEN == '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.EL1PCTEN == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '10' && CNTHCTL_EL2.EL1PCTEN == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && CNTHCTL_EL2.EL0PCTEN == '0' then AArch64.SystemAccessTrap(EL2, 0x18); else if IsFeatureImplemented(FEAT_ECV) && EL2Enabled() && SCR_EL3.ECVEn == '1' && CNTHCTL_EL2.ECV == '1' && HCR_EL2.<E2H,TGE> != '11' then X[t, 64] = PhysicalCountInt() - CNTPOFF_EL2; else X[t, 64] = PhysicalCountInt(); elsif PSTATE.EL == EL1 then if EL2Enabled() && CNTHCTL_EL2.EL1PCTEN == '0' then AArch64.SystemAccessTrap(EL2, 0x18); else if IsFeatureImplemented(FEAT_ECV) && EL2Enabled() && SCR_EL3.ECVEn == '1' && CNTHCTL_EL2.ECV == '1' then X[t, 64] = PhysicalCountInt() - CNTPOFF_EL2; else X[t, 64] = PhysicalCountInt(); elsif PSTATE.EL == EL2 then X[t, 64] = PhysicalCountInt(); elsif PSTATE.EL == EL3 then X[t, 64] = PhysicalCountInt();
04/07/2023 11:25; 1b994cb0b8c6d1ae5a9a15edbc8bd6ce3b5c7d68
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