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ACCDATA_EL1: Accelerator Data

Purpose

Holds the lower 32 bits of the data that is stored by an ST64BV0, Single-copy atomic 64-byte EL0 store instruction.

Configuration

This register is present only when FEAT_LS64_ACCDATA is implemented. Otherwise, direct accesses to ACCDATA_EL1 are UNDEFINED.

Attributes

ACCDATA_EL1 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
RES0
ACCDATA

Bits [63:32]

Reserved, RES0.

ACCDATA, bits [31:0]

Accelerator Data field. Holds bits[31:0] of the data that is stored by an ST64BV0 instruction.

Accessing ACCDATA_EL1

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

MRS <Xt>, ACCDATA_EL1

op0op1CRnCRmop2
0b110b0000b11010b00000b101

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.ADEn == '0' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGRTR_EL2.nACCDATA_EL1 == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.ADEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = ACCDATA_EL1; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.ADEn == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.ADEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = ACCDATA_EL1; elsif PSTATE.EL == EL3 then X[t, 64] = ACCDATA_EL1;

MSR ACCDATA_EL1, <Xt>

op0op1CRnCRmop2
0b110b0000b11010b00000b101

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.ADEn == '0' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGWTR_EL2.nACCDATA_EL1 == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && SCR_EL3.ADEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else ACCDATA_EL1 = X[t, 64]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && SCR_EL3.ADEn == '0' then UNDEFINED; elsif HaveEL(EL3) && SCR_EL3.ADEn == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else ACCDATA_EL1 = X[t, 64]; elsif PSTATE.EL == EL3 then ACCDATA_EL1 = X[t, 64];