GICD_TYPER, Interrupt Controller Type Register

Indicates the maximum INTID in the Extended SPI range.

Maximum Extended SPI INTID is (32*(ESPI_range + 1) + 4095).

The ESPI_range field only indicates the maximum number of SPIs that the GIC implementation might support. This value determines the number of instances of the following interrupt registers:

• GICD_IGROUPR<n>E.
• GICD_ISENABLER<n>E.
• GICD_ICENABLER<n>E.
• GICD_ISPENDR<n>E.
• GICD_ICPENDR<n>E.
• GICD_ISACTIVER<n>E.
• GICD_ICACTIVER<n>E.
• GICD_IPRIORITYR<n>E.
• GICD_ICFGR<n>E.
• GICD_IROUTER<n>E.
• GICD_IGRPMODR<n>E.

The GIC architecture does not require a GIC implementation to support a continuous range of SPI interrupt IDs. Software must check which SPI INTIDs are supported, up to the maximum value indicated by GICD_TYPER.ESPI_range.

Reserved, RES0.

Range Selector Support.

RSS	Meaning
0b0	The IRI supports targeted SGIs with affinity level 0 values of 0 - 15.
0b1	The IRI supports targeted SGIs with affinity level 0 values of 0 - 255.

Indicates whether 1 of N SPI interrupts are supported.

No1N	Meaning
0b0	1 of N SPI interrupts are supported.
0b1	1 of N SPI interrupts are not supported.

Affinity 3 valid. Indicates whether the Distributor supports nonzero values of Affinity level 3.

A3V	Meaning
0b0	The Distributor only supports zero values of Affinity level 3.
0b1	The Distributor supports nonzero values of Affinity level 3.

The number of interrupt identifier bits supported, minus one.

Indicates whether the implementation supports Direct Virtual LPI injection.

DVIS	Meaning
0b0	The implementation does not support Direct Virtual LPI injection.
0b1	The implementation supports Direct Virtual LPI injection.

Reserved, RES0.

Indicates whether the implementation supports LPIs.

LPIS	Meaning
0b0	The implementation does not support LPIs.
0b1	The implementation supports LPIs.

Indicates whether the implementation supports message-based interrupts by writing to Distributor registers.

MBIS	Meaning
0b0	The implementation does not support message-based interrupts by writing to Distributor registers. The GICD_CLRSPI_NSR, GICD_SETSPI_NSR, GICD_CLRSPI_SR, and GICD_SETSPI_SR registers are reserved.
0b1	The implementation supports message-based interrupts by writing to the GICD_CLRSPI_NSR, GICD_SETSPI_NSR, GICD_CLRSPI_SR, or GICD_SETSPI_SR registers.

Number of supported LPIs.

• 0b00000 Number of LPIs as indicated by GICD_TYPER.IDbits.

• All other values Number of LPIs supported is 2^(num_LPIs+1).

  • Available LPI INTIDs are 8192..(8192 + 2^(num_LPIs+1) - 1).

  • This field cannot indicate a maximum LPI INTID greater than that indicated by GICD_TYPER.IDbits.

When the supported INTID width is less than 14 bits, this field is RES0 and no LPIs are supported.

Indicates whether the GIC implementation supports two Security states:

When GICD_CTLR.DS == 1, this field is RAZ.

SecurityExtn	Meaning
0b0	The GIC implementation supports only a single Security state.
0b1	The GIC implementation supports two Security states.

Non-maskable Interrupts.

NMI	Meaning
0b0	Non-maskable interrupt property not supported.
0b1	Non-maskable interrupt property is supported.

Extended SPI.

ESPI	Meaning
0b0	Extended SPI range not implemented.
0b1	Extended SPI range implemented.

Reports the number of PEs that can be used when affinity routing is not enabled, minus 1.

These PEs must be numbered contiguously from zero, but the relationship between this number and the affinity hierarchy from MPIDR is IMPLEMENTATION DEFINED. If the implementation does not support ARE being zero, this field is 000.

For the INTID range 32 to 1019, indicates the maximum SPI supported.

If the value of this field is N, the maximum SPI INTID is 32(N+1) minus 1. For example, 00011 specifies that the maximum SPI INTID in is 127.

Regardless of the range of INTIDs defined by this field, interrupt IDs 1020-1023 are reserved for special purposes.

A value of 0 indicates no SPIs are support.