Invalidate data or unified cache line by set/way.
AArch32 System instruction DCISW performs the same function as AArch64 System instruction DC ISW.
This instruction is present only when FEAT_AA32EL1 is implemented. Otherwise, direct accesses to DCISW are UNDEFINED.
DCISW is a 32-bit System instruction.
| 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 |
| SetWay | Level | RES0 | |||||||||||||||||||||||||||||
Contains two fields:
Bits[L-1:4] are RES0.
A = Log2(ASSOCIATIVITY), L = Log2(LINELEN), B = (L + S), S = Log2(NSETS).
ASSOCIATIVITY, LINELEN (line length, in bytes), and NSETS (number of sets) have their usual meanings and are the values for the cache level being operated on. The values of A and S are rounded up to the next integer.
Cache level to operate on, minus 1. For example, this field is 0 for operations on L1 cache, or 1 for operations on L2 cache.
Reserved, RES0.
If this instruction is executed with a set, way or level argument that is larger than the value supported by the implementation then the behavior is CONSTRAINED UNPREDICTABLE and one of the following occurs:
Accesses to this instruction use the following encodings in the System instruction encoding space:
| coproc | opc1 | CRn | CRm | opc2 |
|---|---|---|---|---|
| 0b1111 | 0b000 | 0b0111 | 0b0110 | 0b010 |
if !IsFeatureImplemented(FEAT_AA32EL1) then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && HSTR_EL2.T7 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HSTR.T7 == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && HCR_EL2.TSW == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HCR.TSW == '1' then AArch32.TakeHypTrapException(0x03); else AArch32.DC(R[t], CacheOp_Invalidate, CacheOpScope_SetWay); elsif PSTATE.EL == EL2 then AArch32.DC(R[t], CacheOp_Invalidate, CacheOpScope_SetWay); elsif PSTATE.EL == EL3 then AArch32.DC(R[t], CacheOp_Invalidate, CacheOpScope_SetWay);