Intel
®
81341 and 81342—Interrupt Controller Unit
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
744
Order Number: 315037-002US
11.4
Intel
®
81341 and 81342 I/O Processors
External
Interrupt Interface
The interrupt controller attached to the Intel XScale
®
processor has the facilities
necessary to handle all core processor and peripheral internal interrupts as well as the
sixteen external interrupts (
XINT[15:0]#
) and a high priority interrupt (
HPI#
).
The81341 and 81342 Primary PCI local bus interface includes four interrupt output
signals (
XINT[3:0]#
/
P_INT[D:A]#
). Interrupts from the Messaging Unit and Address
Translation Units are routed to these interrupt output signals.
11.4.1
Interrupt Inputs
The 17 external interrupt input pins of the 81341 and 81342 have the following
definitions:
XINT[3:0]# External Interrupt (Input)
— These pins (
XINT[3:0]#
) cause
interrupts to be requested. Each pin is a level-detect input only. These
pins are internally synchronized. These pins act as interrupt inputs and
must be unmasked in the INTCTL[3:0] registers. These pins also act as
interrupt outputs (
P_INT[D:A]#
) for the PCI-X interface when
configured as an endpoint. These pins can also function as general
purpose inputs/outputs (
GPIO[11:8]
) when not used as interrupt pins.
XINT[7:4]# External Interrupt (Input)
— These pins (
XINT[7:4]#
) cause
interrupts to be requested. Each pin is a level-detect input only. These
pins are internally synchronized. These pins only act as interrupt inputs
when they are unmasked in the INTCTL[3:0] registers. These pins can
also function as general purpose inputs/outputs (
GPIO[15:12]
) when
not used as interrupt pins.
XINT[15:8]#
External Interrupt (Input)
— These pins (
XINT[15:8]#
) cause
interrupts to be requested. Each pin is a level-detect input only. These
pins are internally synchronized. These pins only act as interrupt inputs
when they are configured as general purpose inputs and are unmasked
in the INTCTL[3:0] registers. These pins can also function as general
purpose inputs/outputs (
GPIO[7:0]
) when not used as interrupt pins.
HPI#
High-Priority Interrupt (Input)
— Causes a high priority interrupt
event to occur. The external
HPI#
input requires a level input and is
maskable by the INTCTL[3:0] registers. This pin is internally
synchronized.
NMI0#
Non-Maskable Interrupt 0 (Input)
— Causes a non-maskable
imprecise data abort exception to the Intel XScale
®
processor 0. The
external
NMI0#
input requires a falling edge triggered input. This pin is
internally synchronized.
NMI1#
Non-Maskable Interrupt 1 (Input)
— Causes a non-maskable
imprecise data abort exception to the Intel XScale
®
processor 1. The
external
NMI1#
input requires a falling edge triggered input. This pin is
internally synchronized.
Note:
NMI0#
and
NMI1#
are not implemented as part of the Interrupt Controller Units.
They are external pins which are falling edge triggered, internally synchronized and
then directly driven to the respectively Intel XScale
®
processors.