12th Generation Intel® Core™ Processors Datasheet Volume 2 of 2
ID | Date | Version | Classification |
---|---|---|---|
767625 | 07/13/2023 | Public |
I/O Base Address (IOBAR_0_2_0_PCI) – Offset 20
This register provides the Base offset of the I/O registers within Device #2.
Bits 15:6 are programmable allowing the I/O Base to be located anywhere in 16bit I/O Address Space.
Bits 2:1 are fixed and return zero
Bit 0 is hardwired to a one indicating that 8 bytes of I/O space are decoded.
Access to the 8Bs of IO space is allowed in PM state D0 when IO Enable (PCICMD bit 0) set.
Access is disallowed in PM states D1-D3 or if IO Enable is clear or if Device #2 is turned off or if Internal graphics is disabled.
Note that access to this IO BAR is independent of VGA functionality within Device #2.
If accesses to this IO bar is allowed then all 8, 16 or 32 bit IO cycles from IA cores that falls within the 8B are claimed.
This IO BAR can be disabled and hidden from system software via DEV2CTL[0] IOBARDIS at offset 0x58.
Bit Range | Default | Access | Field Name and Description |
---|---|---|---|
31:16 | 0x0 | RSV | RESERVED (Reserved_0) The field 'Reserved' in register 'I/O Base Address' does not have a description in the BXML |
15:6 | 0x0 | RW/V/L | IO Base Address (IOBASE) Set by the OS, these bits correspond to address signals [15:6]. Note: This field is RO 0's if DEV2CTL[0] IOBARDIS is 1b. |
5:3 | 0x0 | RSV | RESERVED (Reserved_1) The field 'Reserved' in register 'I/O Base Address' does not have a description in the BXML |
2:1 | 0x0 | RO | Memory Type (MEMTYPE) Hardwired to 0s to indicate 32-bit address. |
0 | 0x1 | RO | Memory I/O Space (MIOS) Hardwired to '1' to indicate IO space. Note: This field is RO 0's if DEV2CTL[0] IOBARDIS is 1b. |