Holds the 64-bit virtual offset. This is the offset between the physical count value visible in CNTPCT and the virtual count value visible in CNTVCT.
AArch32 System register CNTVOFF bits [63:0] are architecturally mapped to AArch64 System register CNTVOFF_EL2[63:0].
This register is present only when EL2 is capable of using AArch32. Otherwise, direct accesses to CNTVOFF are UNDEFINED.
If EL2 is not implemented, this register is RES0 from EL3 and the virtual counter uses a fixed virtual offset of zero.
When the Effective value of HCR_EL2.{E2H, TGE} is {1, 1}, the virtual counter uses a fixed virtual offset of zero when CNTVCT is read from Non-secure EL0.
CNTVOFF 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 |
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Virtual offset.
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:
Accesses to this register use the following encodings in the System register encoding space:
MRRC{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <Rt2>, <CRm>
| coproc | CRm | opc1 |
|---|---|---|
| 0b1111 | 0b1110 | 0b0100 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then UNDEFINED; elsif PSTATE.EL == EL2 then (R[t2], R[t]) = (CNTVOFF<63:32>, CNTVOFF<31:0>); elsif PSTATE.EL == EL3 then if SCR.NS == '0' then UNDEFINED; else (R[t2], R[t]) = (CNTVOFF<63:32>, CNTVOFF<31:0>);
MCRR{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <Rt2>, <CRm>
| coproc | CRm | opc1 |
|---|---|---|
| 0b1111 | 0b1110 | 0b0100 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then UNDEFINED; elsif PSTATE.EL == EL2 then CNTVOFF = R[t2]:R[t]; elsif PSTATE.EL == EL3 then if SCR.NS == '0' then UNDEFINED; else CNTVOFF = R[t2]:R[t];