CNTVCT

Holds the 64-bit virtual count value. The virtual count value is equal to the physical count value minus the virtual offset visible in CNTVOFF.

Configuration

AArch32 System register CNTVCT bits [63:0] are architecturally mapped to AArch64 System register CNTVCT_EL0[63:0].

This register is present only when AArch32 is supported. Otherwise, direct accesses to CNTVCT are UNDEFINED.

The value of this register is the same as the value of CNTPCT in the following conditions:

All reads to the CNTVCT occur in program order relative to reads to CNTVCTSS or CNTVCT.

Attributes

Field descriptions

Bits [63:0]

Accessing CNTVCT

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	0b0001

if PSTATE.EL == EL0 then if !ELUsingAArch32(EL1) && !ELIsInHost(EL0) && CNTKCTL_EL1.EL0VCTEN == '0' then if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TGE == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x04); else AArch64.AArch32SystemAccessTrap(EL1, 0x04); elsif ELUsingAArch32(EL1) && CNTKCTL.PL0VCTEN == '0' then if EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TGE == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x04); elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.TGE == '1' then AArch32.TakeHypTrapException(0x00); else UNDEFINED; elsif ELIsInHost(EL0) && CNTHCTL_EL2.EL0VCTEN == '0' then AArch64.AArch32SystemAccessTrap(EL2, 0x04); elsif EL2Enabled() && !ELUsingAArch32(EL2) && !ELIsInHost(EL0) && CNTHCTL_EL2.EL1TVCT == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x04); else if HaveEL(EL2) && !ELUsingAArch32(EL2) && (!EL2Enabled() || !ELIsInHost(EL0)) then (R[t2], R[t]) = Split(PhysicalCountInt() - CNTVOFF_EL2, 32); elsif HaveEL(EL2) && ELUsingAArch32(EL2) then (R[t2], R[t]) = Split(PhysicalCountInt() - CNTVOFF, 32); else (R[t2], R[t]) = Split(PhysicalCountInt(), 32); elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && CNTHCTL_EL2.EL1TVCT == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x04); else if HaveEL(EL2) && !ELUsingAArch32(EL2) then (R[t2], R[t]) = Split(PhysicalCountInt() - CNTVOFF_EL2, 32); elsif HaveEL(EL2) && ELUsingAArch32(EL2) then (R[t2], R[t]) = Split(PhysicalCountInt() - CNTVOFF, 32); else (R[t2], R[t]) = Split(PhysicalCountInt(), 32); elsif PSTATE.EL == EL2 then (R[t2], R[t]) = Split(PhysicalCountInt() - CNTVOFF, 32); elsif PSTATE.EL == EL3 then if HaveEL(EL2) then (R[t2], R[t]) = Split(PhysicalCountInt() - CNTVOFF, 32); else (R[t2], R[t]) = Split(PhysicalCountInt(), 32);

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
Virtual count value
Virtual count value