ICH_EISR, Interrupt Controller End of Interrupt Status Register

The ICH_EISR characteristics are:

Purpose

Indicates which List registers have outstanding EOI maintenance interrupts.

Configuration

AArch32 System register ICH_EISR bits [31:0] are architecturally mapped to AArch64 System register ICH_EISR_EL2[31:0] .

This register is present only when AArch32 is supported at any Exception level. Otherwise, direct accesses to ICH_EISR are UNDEFINED.

If EL2 is not implemented, this register is RES0 from EL3.

Attributes

ICH_EISR is a 32-bit register.

Field descriptions

The ICH_EISR bit assignments are:

Bits [31:16]

Reserved, RES0.

Status<n>, bit [n], for n = 0 to 15

EOI maintenance interrupt status bit for List register <n>:

For any ICH_LR<n>, the corresponding status bit is set to 1 if all of the following are true:

• ICH_LRC<n>.State is 0b00.
• ICH_LRC<n>.HW is 0.
• ICH_LRC<n>.EOI (bit [9]) is 1, indicating that when the interrupt corresponding to that List register is deactivated, a maintenance interrupt is asserted.

This field resets to 0.

if PSTATE.EL == EL0 then
    UNDEFINED;
elsif PSTATE.EL == EL1 then
    if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T12 == '1' then
        AArch64.AArch32SystemAccessTrap(EL2, 0x03);
    elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T12 == '1' then
        AArch32.TakeHypTrapException(0x03);
    else
        UNDEFINED;
elsif PSTATE.EL == EL2 then
    if ICC_HSRE.SRE == '0' then
        UNDEFINED;
    else
        return ICH_EISR;
elsif PSTATE.EL == EL3 then
    if ICC_MSRE.SRE == '0' then
        UNDEFINED;
    else
        return ICH_EISR;