The TRCCCCTLR characteristics are:
Set the threshold value for cycle counting.
AArch64 System register TRCCCCTLR bits [31:0] are architecturally mapped to External register TRCCCCTLR[31:0].
This register is present only when FEAT_ETE is implemented and TRCIDR0.TRCCCI == 1. Otherwise, direct accesses to TRCCCCTLR are UNDEFINED.
TRCCCCTLR 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 |
RES0 | |||||||||||||||||||||||||||||||
RES0 | THRESHOLD |
Reserved, RES0.
Sets the threshold value for instruction trace cycle counting.
The minimum threshold value that can be programmed into THRESHOLD is given in TRCIDR3.CCITMIN. If the THRESHOLD value is smaller than the value in TRCIDR3.CCITMIN then the behavior is CONSTRAINED UNPREDICTABLE. That is, cycle counts might or might not be included in the trace and the cycle count threshold is not known.
Writing a value of zero when TRCCONFIGR.CCI enables instruction trace cycle counting results in CONSTRAINED UNPREDICTABLE behavior. That is, cycle counts might or might not be included in the trace and the cycle count threshold is not known.
The reset behaviour of this field is:
Must be programmed if TRCCONFIGR.CCI == 1.
Writes are CONSTRAINED UNPREDICTABLE if the trace unit is not in the Idle state.
Accesses to this register use the following encodings in the System register encoding space:
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b10 | 0b001 | 0b0000 | 0b1110 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && CPTR_EL3.TTA == '1' then UNDEFINED; elsif CPACR_EL1.TTA == '1' then AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && CPTR_EL2.TTA == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGRTR_EL2.TRC == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && CPTR_EL3.TTA == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else return TRCCCCTLR; elsif PSTATE.EL == EL2 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && CPTR_EL3.TTA == '1' then UNDEFINED; elsif CPTR_EL2.TTA == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && CPTR_EL3.TTA == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else return TRCCCCTLR; elsif PSTATE.EL == EL3 then if CPTR_EL3.TTA == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else return TRCCCCTLR;
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b10 | 0b001 | 0b0000 | 0b1110 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && CPTR_EL3.TTA == '1' then UNDEFINED; elsif CPACR_EL1.TTA == '1' then AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && CPTR_EL2.TTA == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGWTR_EL2.TRC == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && CPTR_EL3.TTA == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else TRCCCCTLR = X[t]; elsif PSTATE.EL == EL2 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && CPTR_EL3.TTA == '1' then UNDEFINED; elsif CPTR_EL2.TTA == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && CPTR_EL3.TTA == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else TRCCCCTLR = X[t]; elsif PSTATE.EL == EL3 then if CPTR_EL3.TTA == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else TRCCCCTLR = X[t];
30/06/2021 15:22; 2a17f7750cfd1ab239f20f6cf29877ba8041794f
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