The ICH_ELRSR characteristics are:
Indicates which List registers contain valid interrupts.
This register is part of:
AArch32 System register ICH_ELRSR is architecturally mapped to AArch64 System register ICH_ELRSR_EL2.
If EL2 is not implemented, this register is RES0 from EL3.
ICH_ELRSR is a 32-bit register.
The ICH_ELRSR bit assignments are:
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 |
0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | Status<n>, bit [n], for n = 0 to 15 |
Reserved, RES0.
Status bit for List register <n>, ICH_LR<n>:
Status<n> | Meaning |
---|---|
0 |
List register ICH_LR<n>, if implemented, contains a valid interrupt. Using this List register can result in overwriting a valid interrupt. |
1 |
List register ICH_LR<n> does not contain a valid interrupt. The List register is empty and can be used without overwriting a valid interrupt or losing an EOI maintenance interrupt. |
For any List register <n>, the corresponding status bit is set to 1 if ICH_LRC<n>.State is 0b00 and either ICH_LRC<n>.HW is 1 or ICH_LRC<n>.EOI (bit [9]) is 0.
This register can be read using MRC with the following syntax:
MRC <syntax>
This syntax uses the following encoding in the System instruction encoding space:
<syntax> | opc1 | opc2 | CRn | coproc | CRm |
---|---|---|---|---|---|
p15, 4, <Rt>, c12, c11, 5 | 100 | 101 | 1100 | 1111 | 1011 |
The register is accessible as follows:
Control | Accessibility | ||||
---|---|---|---|---|---|
TGE | NS | EL0 | EL1 | EL2 | EL3 |
x | 0 | - | - | n/a | - |
0 | 1 | - | - | RO | RO |
1 | 1 | - | n/a | RO | RO |
This table applies to all instructions that can access this register.
For a description of the prioritization of any generated exceptions, see section G1.11.2 (Exception priority order) in the ARM® Architecture Reference Manual, ARMv8, for ARMv8-A architecture profile for exceptions taken to AArch32 state, and section D1.13.2 (Synchronous exception prioritization) for exceptions taken to AArch64 state. Subject to the prioritization rules, the following traps and enables are applicable when accessing this register.
In both Security states, and not dependent on other configuration bits:
If ICC_HSRE.SRE==0, read accesses to this register from EL2 are UNDEFINED.
If ICC_MSRE.SRE==0, Non-secure read accesses to this register from EL3 are UNDEFINED.
When EL2 is implemented and is using AArch64 and SCR_EL3.NS==1 :
If HSTR_EL2.T12==1, Non-secure accesses to this register from EL1 are trapped to EL2.
When EL2 is implemented and is using AArch64 and SCR_EL3.NS==1 && HCR_EL2.TGE==0 :
If HSTR_EL2.T12==1, Non-secure accesses to this register from EL1 are trapped to EL2.
When EL2 is implemented and is using AArch32 and SCR_EL3.NS==1 :
If HSTR.T12==1, Non-secure accesses to this register from EL1 are trapped to Hyp mode.
28/09/2017 08:24
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