Intel® Core™ Ultra Series 3 Processors I/O Registers
| ID | Date | Version | Classification |
|---|---|---|---|
| 872352 | 04/14/2026 | 001 | Public |
Host PCI Configuration Control (HfPCICFGCTL) – Offset 1c70
This register controls PCI function (host root space) general behaviors.
| Bit Range | Default | Access | Field Name and Description |
|---|---|---|---|
| 15:8 | 0h | RW | ACPI Interrupt Number (ACPIIN) Indicates the IRQ number that the PCI function uses when generating ACPI interrupt. |
| 7 | 1h | RW | Shadowed PCI Configuration Base Address Disable (SPCBAD) SPCBA register in the PCI configuration space becomes read-only when this bit is set. |
| 6:2 | 0h | RO | Reserved (Preserved) (RSVD6) SW must preserve the original value when writing. |
| 1 | 0h | RW | ACPI Interrupt Enable (ACPIIE) When set, the IOSF Sideband interface uses ACPI SB opcodes for messages. |
| 0 | 0h | RW | PCI Configuration Disable (PCICD) When set, the PCI configuration accesses return UR response. |