©2008 Advanced Micro Devices, Inc. IOXAPIC Registers
AMD SB600 Register Reference Manual Proprietary Page 297
4.5.2 Indirect Access Registers
Software needs to first select the register to access using the IO Register Select Register, and then read or
write using the IO Window Register.
IOAPIC ID Register [Indirect Address Offset = 00H] RW
Field Name Bits Default Description
<reserved> 23:0 000000h
ID 27:24 0h IOAPIC device ID for APIC serial bus delivery mode
<reserved> 31:28 0h
Not used in XAPIC PCI bus delivery mode.
IOXAPIC Version Register [Indirect Address Offset = 01H] R
Field Name Bits Default Description
Version 7:0 21h PCI 2.2 compliant
<Reserved> 14:8 00h
PRQ 15 1b IRQ pin assertion supported
Max Redirection Entries 23:16 17h 24 entries [23:0]
<Reserved> 31:24 00h
IOAPIC Arbitration Register [Indirect Address Offset = 02H] R
Field Name Bits Default Description
<reserved> 23:0 000000h
Arbitration ID 27:24 0h Arbitration ID for APIC serial bus delivery mode
<reserved> 31:28 0h
Not used in XAPIC PCI bus delivery mode.
Redirection Table Entry [0–23] [Indirect Address Offset = 11/10H–3F/3EH] RW
Field Name Bits Default Description
Vector 7:0 00h Interrupt vector associated with this interrupt input
Delivery Mode 10:8 0h 000 – Fixed
001 – Lowest Priority
010 – SMI/PMI
011 – <reserved>
100 – NMI
101 – INIT
110 – <Reserved>
111 �� ExtINT
Destination Mode 11 0b 0 – Physical
1 – Logical
Delivery Status 12 0b Read Only
0 – Idle
1 – Send Pending
Interrupt Pin Polarity 13 0b 0 – Hig h
1 – Low
Remote IRR 14 0b Read Only.
Used for level triggered interrupts only.
Set when interrupt message delivered.
Cleared by EOI special cycle transaction or write to
EOI register
Trigger Mode 15 0b 0 – Edge
1 – Level
Mask 16 1b Mask the interrupt injection at the input of this device
Write 0 to unmask
Reserved 31:17 0000h
Reserved 55:32 000000h