GICH_MISR, Maintenance Interrupt Status Register

The GICH_MISR characteristics are:

Purpose

Indicates which maintenance interrupts are asserted.

Configuration

This register is present only when FEAT_GICv3_LEGACY is implemented and EL2 is implemented. Otherwise, direct accesses to GICH_MISR are RES0.

This register is available when the GIC implementation supports interrupt virtualization.

Attributes

GICH_MISR is a 32-bit register.

Field descriptions

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																								VGrp1D	VGrp1E	VGrp0D	VGrp0E	NP	LRENP	U	EOI

Bits [31:8]

Reserved, RES0.

VGrp1D, bit [7]

vPE Group 1 Disabled.

VGrp1D	Meaning
0b0	vPE Group 1 Disabled maintenance interrupt not asserted.
0b1	vPE Group 1 Disabled maintenance interrupt asserted.

This maintenance interrupt is asserted when GICH_HCR.VGrp1DIE == 1 and GICH_VMCR.VENG1 == 0.

The reset behavior of this field is:

On a Warm reset, this field resets to 0.

VGrp1E, bit [6]

vPE Group 1 Enabled.

VGrp1E	Meaning
0b0	vPE Group 1 Enabled maintenance interrupt not asserted.
0b1	vPE Group 1 Enabled maintenance interrupt asserted.

This maintenance interrupt is asserted when GICH_HCR.VGrp1EIE == 1 and GICH_VMCR.VENG1 == 1.

The reset behavior of this field is:

On a Warm reset, this field resets to 0.

VGrp0D, bit [5]

vPE Group 0 Disabled.

VGrp0D	Meaning
0b0	vPE Group 0 Disabled maintenance interrupt not asserted.
0b1	vPE Group 0 Disabled maintenance interrupt asserted.

This maintenance interrupt is asserted when GICH_HCR.VGrp0DIE == 1 and GICH_VMCR.VENG0 == 0.

The reset behavior of this field is:

On a Warm reset, this field resets to 0.

VGrp0E, bit [4]

vPE Group 0 Enabled.

VGrp0E	Meaning
0b0	vPE Group 0 Enabled maintenance interrupt not asserted.
0b1	vPE Group 0 Enabled maintenance interrupt asserted.

This maintenance interrupt is asserted when GICH_HCR.VGrp0EIE == 1 and GICH_VMCR.VENG0 == 1.

The reset behavior of this field is:

On a Warm reset, this field resets to 0.

NP, bit [3]

No Pending.

NP	Meaning
0b0	No Pending maintenance interrupt not asserted.
0b1	No Pending maintenance interrupt asserted.

This maintenance interrupt is asserted when GICH_HCR.NPIE == 1 and no List register is in the pending state.

The reset behavior of this field is:

On a Warm reset, this field resets to 0.

LRENP, bit [2]

List Register Entry Not Present.

LRENP	Meaning
0b0	List Register Entry Not Present maintenance interrupt not asserted.
0b1	List Register Entry Not Present maintenance interrupt asserted.

This maintenance interrupt is asserted when GICH_HCR.LRENPIE == 1 and GICH_HCR.EOICount is nonzero.

The reset behavior of this field is:

On a Warm reset, this field resets to 0.

U, bit [1]

Underflow.

U	Meaning
0b0	Underflow maintenance interrupt not asserted.
0b1	Underflow maintenance interrupt asserted.

This maintenance interrupt is asserted when GICH_HCR.UIE == 1 and zero or one of the List register entries are marked as a valid interrupt.

The reset behavior of this field is:

On a Warm reset, this field resets to 0.

EOI, bit [0]

End Of Interrupt.

EOI	Meaning
0b0	End Of Interrupt maintenance interrupt not asserted.
0b1	End Of Interrupt maintenance interrupt asserted.

This maintenance interrupt is asserted when at least one bit in GICH_EISR == 1.

The reset behavior of this field is:

On a Warm reset, this field resets to 0.

Note

A List register is in the pending state only if the corresponding GICH_LR<n> value is 0b01, that is, pending. The active and pending state is not included.

Accessing GICH_MISR

This register is used only when System register access is not enabled. When System register access is enabled:

For AArch32 implementations, ICH_MISR provides equivalent functionality.
For AArch64 implementations, ICH_MISR_EL2 provides equivalent functionality.

A maintenance interrupt is asserted only if at least one bit is set to 1 in this register and if GICH_HCR.En == 1.

GICH_MISR can be accessed through the memory-mapped interfaces:

Component	Offset	Instance
GIC Virtual interface control	0x0010	GICH_MISR

This interface is accessible as follows:

When GICD_CTLR.DS == 0, accesses to this register are RO.
When an access is Secure, accesses to this register are RO.
When an access is Non-secure, accesses to this register are RO.

04/07/2023 11:23; 1b994cb0b8c6d1ae5a9a15edbc8bd6ce3b5c7d68

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