CNTVCTSS

Holds the 64-bit virtual count value. The virtual count value is equal to the physical count value visible in CNTPCT_EL0 minus the virtual offset visible in CNTVOFF_EL2.

Configuration

AArch64 System register CNTVCTSS_EL0 bits [63:0] are architecturally mapped to AArch32 System register CNTVCTSS[63:0].

This register is present only when FEAT_ECV is implemented. Otherwise, direct accesses to CNTVCTSS_EL0 are UNDEFINED.

All reads to the CNTVCTSS_EL0 occur in program order relative to reads to CNTVCT_EL0 or CNTVCTSS_EL0.

This register is a self-synchronised view of the CNTVCT_EL0 counter, and cannot be read speculatively.

Attributes

Field descriptions

Bits [63:0]

Accessing CNTVCTSS_EL0

Accesses to this register use the following encodings in the System register encoding space:

MRS <Xt>, CNTVCTSS_EL0

op0	op1	CRn	CRm	op2
0b11	0b011	0b1110	0b0000	0b110

if PSTATE.EL == EL0 then if !(EL2Enabled() && HCR_EL2.<E2H,TGE> == '11') && CNTKCTL_EL1.EL0VCTEN == '0' then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && CNTHCTL_EL2.EL0VCTEN == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && HCR_EL2.<E2H,TGE> != '11' && CNTHCTL_EL2.EL1TVCT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else if HaveEL(EL2) && (!EL2Enabled() || HCR_EL2.<E2H,TGE> != '11') then X[t, 64] = PhysicalCountInt() - CNTVOFF_EL2; else X[t, 64] = PhysicalCountInt(); elsif PSTATE.EL == EL1 then if EL2Enabled() && CNTHCTL_EL2.EL1TVCT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else if HaveEL(EL2) then X[t, 64] = PhysicalCountInt() - CNTVOFF_EL2; else X[t, 64] = PhysicalCountInt(); elsif PSTATE.EL == EL2 then if HCR_EL2.E2H == '0' then X[t, 64] = PhysicalCountInt() - CNTVOFF_EL2; else X[t, 64] = PhysicalCountInt(); elsif PSTATE.EL == EL3 then if HaveEL(EL2) && !ELUsingAArch32(EL2) then X[t, 64] = PhysicalCountInt() - CNTVOFF_EL2; elsif HaveEL(EL2) && ELUsingAArch32(EL2) then X[t, 64] = PhysicalCountInt() - CNTVOFF; else X[t, 64] = PhysicalCountInt();

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
Self-synchronized virtual count value
Self-synchronized virtual count value