Revision 1.02 – April 12, 2007
S5920 – PCI Product: PCI Configuration Registers
Data Book
This register indicates the interrupt routing for the
S5920 controller. The ultimate value for this register is
system-architecture specific. For x86 based PCs, the
values in this register correspond with the established
interrupt numbers associated with the dual 8259 con-
trollers used in those machines. In x86-based PC
systems, the values of 0 to 15 correspond with the IRQ
numbers 0 through 15, and the values from 16 to 254
are reserved. The value of 255 (the controller’s default
power-up value) signifies either “unknown” or “no con-
nection” for the system interrupt. This register is boot-
loaded from the external boot memory or may be writ-
ten by the PCI interface.
INTERRUPT LINE REGISTER (INTLN)
Interrupt Line
Register Name:
3Ch
Address Offset:
Power-up value:
Boot-load:
Attribute:
FFh
External nvRAM offset 7Ch
Read/Write
8 bits
Size:
Figure 22. Interrupt Line Register
7
0
FFh
AMCC Confidential and Proprietary
DS1596
67
AMCC [ APPLIED MICRO CIRCUITS CORPORATION ]
