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# ICC_SGI0R, Interrupt Controller Software Generated Interrupt Group 0 Register

The ICC_SGI0R characteristics are:

## Purpose

Generates Secure Group 0 SGIs.

## Configuration

AArch32 System register ICC_SGI0R performs the same function as AArch64 System register ICC_SGI0R_EL1.

This register is present only when EL1 is capable of using AArch32 and GICv3 is implemented. Otherwise, direct accesses to ICC_SGI0R are UNDEFINED.

## Attributes

ICC_SGI0R is a 64-bit register.

## Field descriptions

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 | Aff3 | RS | RES0 | IRM | Aff2
RES0 | INTID | Aff1 | TargetList

#### Bits [63:56]

Reserved, RES0.

#### Aff3, bits [55:48]

The affinity 3 value of the affinity path of the cluster for which SGI interrupts will be generated.

If the IRM bit is 1, this field is RES0.

#### RS, bits [47:44]

RangeSelector

Controls which group of 16 values is represented by the TargetList field.

TargetList[n] represents aff0 value ((RS * 16) + n).

When ICC_CTLR_EL1.RSS==0, RS is RES0.

When ICC_CTLR_EL1.RSS==1 and GICD_TYPER.RSS==0, writing this register with RS != 0 is a CONSTRAINED UNPREDICTABLE choice of :

- The write is ignored.
- The RS field is treated as 0.

#### Bits [43:41]

Reserved, RES0.

#### IRM, bit [40]

Interrupt Routing Mode. Determines how the generated interrupts are distributed to PEs. Possible values are:

IRM | Meaning
--- | ---
0b0 | Interrupts routed to the PEs specified by Aff3.Aff2.Aff1.<target list>.
0b1 | Interrupts routed to all PEs in the system, excluding "self".

#### Aff2, bits [39:32]

The affinity 2 value of the affinity path of the cluster for which SGI interrupts will be generated.

If the IRM bit is 1, this field is RES0.

#### Bits [31:28]

Reserved, RES0.

#### INTID, bits [27:24]

The INTID of the SGI.

#### Aff1, bits [23:16]

The affinity 1 value of the affinity path of the cluster for which SGI interrupts will be generated.

If the IRM bit is 1, this field is RES0.

#### TargetList, bits [15:0]

Target List. The set of PEs for which SGI interrupts will be generated. Each bit corresponds to the PE within a cluster with an Affinity 0 value equal to the bit number.

Note

If SRE is set only for Secure EL3, software executing at EL3 might use the System register interface to generate SGIs. Therefore, the Distributor must always be able to receive and acknowledge Generate SGI packets received from CPU interface regardless of the ARE settings for a Security state. However, the Distributor might discard such packets.

If the IRM bit is 1, this field is RES0.

If a bit is 1 and the bit does not correspond to a valid target PE, the bit must be ignored by the Distributor. It is IMPLEMENTATION DEFINED whether, in such cases, a Distributor can signal a system error.

## Accessing ICC_SGI0R

This register allows software executing in a Secure state to generate Group 0 SGIs. It will also allow software executing in a Non-secure state to generate Group 0 SGIs, if permitted by the settings of GICR_NSACR in the Redistributor corresponding to the target PE.

When GICD_CTLR.DS==0, Non-secure writes do not generate an interrupt for a target PE if not permitted by the GICR_NSACR register associated with the target PE. For more information, see 'Use of control registers for SGI forwarding' in ARM® Generic Interrupt Controller Architecture Specification, GIC architecture version 3.0 and version 4.0 (ARM IHI 0069).

Note

Accesses from Secure Monitor mode are treated as Secure regardless of the value of SCR.NS.

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

#### MCRR{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <Rt2>, <CRm>

coproc | CRm | opc1
--- | --- | ---
0b1111 | 0b1100 | 0b0010

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && SCR_EL3.<IRQ,FIQ> == '11' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && ELUsingAArch32(EL3) && PSTATE.M != M32_Monitor && SCR.<IRQ,FIQ> == '11' then UNDEFINED; elsif EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T12 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T12 == '1' then AArch32.TakeHypTrapException(0x03); elsif ICC_SRE.SRE == '0' then UNDEFINED; elsif EL2Enabled() && !ELUsingAArch32(EL2) && ICH_HCR_EL2.TC == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && ICH_HCR.TC == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.FMO == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.IMO == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.FMO == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.IMO == '1' then AArch32.TakeHypTrapException(0x03); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.<IRQ,FIQ> == '11' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x03); elsif HaveEL(EL3) && ELUsingAArch32(EL3) && PSTATE.M != M32_Monitor && SCR.<IRQ,FIQ> == '11' then if EL3SDDUndef() then UNDEFINED; else AArch32.TakeMonitorTrapException(); else ICC_SGI0R = R[t2]:R[t]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && SCR_EL3.<IRQ,FIQ> == '11' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && ELUsingAArch32(EL3) && SCR.<IRQ,FIQ> == '11' then UNDEFINED; elsif ICC_HSRE.SRE == '0' then UNDEFINED; elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.<IRQ,FIQ> == '11' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x03); elsif HaveEL(EL3) && ELUsingAArch32(EL3) && SCR.<IRQ,FIQ> == '11' then if EL3SDDUndef() then UNDEFINED; else AArch32.TakeMonitorTrapException(); else ICC_SGI0R = R[t2]:R[t]; elsif PSTATE.EL == EL3 then if ICC_MSRE.SRE == '0' then UNDEFINED; else ICC_SGI0R = R[t2]:R[t];

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26/03/2024 09:49; 67c0ae5282a7629ba0ea0ba7267b43cd4f7939f6

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