Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
751
Interrupt Controller Unit—Intel
®
81341 and 81342
11.5.3
Intel
®
81341 and 81342 I/O Processors: Internal Peripheral
Interrupt
The 81341 and 81342 Interrupt Controller receives inputs from multiple internal
interrupt sources. All pending interrupts required during normal operation of the
various peripheral units are available in either the IINTSRC[3:0] or FINTSRC[3:0]
registers depending on the value in INTSTR[3:0]. To provide the best latency for high
performance event driven activities, the Application DMAs interrupts are fully
demultiplexed into the interrupt source registers for FIQ and IRQ so that software does
not need to access these peripheral units to diagnose the exact source and cause of the
interrupt. The IINTSRC[3:0] and the FINTSRC[3:0] registers also include pending
interrupts that indicate that an error has occurred in one of the peripheral units. For the
interrupts that indicate errors, more detail about the exact cause of the interrupt can
be determined by reading the status register of the respective peripheral unit.