Intel
®
81341 and 81342—Interrupt Controller Unit
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
760
Order Number: 315037-002US
11.7.3
IRQ Interrupt Vector Register — IINTVEC
The IRQ Interrupt Vector Register is a 32-bit Coprocessor 6 control register. Following
an IRQ exception, the IRQ interrupt service routine reads the 32-bit vector to the ISR
for the active IRQ source with the highest priority.
The actual vector value is a function of the INTBASE and the INTSIZE registers and is
based on a fixed order of all 128 possible interrupt sources. The vectors begin at
INTBASE with source 0 (i.e., IINTSRC0 bit 0), and end at I INTSIZE (per
source)*127 with source 127 (that is, IINTSRC3 bit 31).
Before returning to User Mode from Interrupt Mode, the software reads the IINTVEC
register and process any lower priority IRQ sources that are active. When there are no
longer any active IRQ sources, a read from the IINTVEC register returns FFFF FFFFH.
Table 460. IRQ Interrupt Vector Register- IINTVEC
Bit
Default
Description
31:00
00000000H IRQ Interrupt Vector—Vector to the highest priority active IRQ source. This register reads FFFF FFFFH
when there are no active IRQ sources.
Memory
Coprocessor
Attributes
Attributes
28
24
20
16
12
8
4
0
31
ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro
na na na na na na na na na na na na na na na na na na na na na na na na na na na na na na na na
Attribute Legend:
RV = Reserved
PR = Preserved
RS = Read/Set
RW = Read/Write
RC = Read Clear
RO = Read Only
NA = Not Accessible
Intel XScale
®
processor Coprocessor address
CP6, Page 2, Register 3