Atmel Evaluation Kit AT91SAM9M10-G45-EK AT91SAM9M10-G45-EK Data Sheet

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SAM9M10 [DATASHEET]

6355F–ATARM–12-Mar-13

The Advanced Interrupt Controller (AIC) is an 8-level priority, individually maskable, vectored interrupt controller,
providing handling of up to thirty-two interrupt sources. It is designed to substantially reduce the software and real-
time overhead in handling internal and external interrupts.

The AIC drives the nFIQ (fast interrupt request) and the nIRQ (standard interrupt request) inputs of an ARM pro-
cessor. Inputs of the AIC are either internal peripheral interrupts or external interrupts coming from the product's
pins.

The 8-level Priority Controller allows the user to define the priority for each interrupt source, thus permitting higher
priority interrupts to be serviced even if a lower priority interrupt is being treated. 

Internal interrupt sources can be programmed to be level sensitive or edge triggered. External interrupt sources
can be programmed to be positive-edge or negative-edge triggered or high-level or low-level sensitive.

The fast forcing feature redirects any internal or external interrupt source to provide a fast interrupt rather than a
normal interrupt. 

• Controls the interrupt lines (nIRQ and nFIQ) of the ARM Processor

• Thirty-two individually maskable and vectored interrupt sources

– Source 0 is reserved for the Fast Interrupt Input (FIQ)

– Source 1 is reserved for system peripherals (PIT, RTT, PMC, DBGU, etc.)

– Programmable Edge-triggered or Level-sensitive Internal Sources

– Programmable Positive/Negative Edge-triggered or High/Low Level-sensitive

• One External Sources plus the Fast Interrupt signal

• 8-level Priority Controller

– Drives the Normal Interrupt of the processor

– Handles priority of the interrupt sources 1 to 31

– Higher priority interrupts can be served during service of lower priority interrupt

• Vectoring

– Optimizes Interrupt Service Routine Branch and Execution

– One 32-bit Vector Register per interrupt source

– Interrupt Vector Register reads the corresponding current Interrupt Vector

• Protect Mode

– Easy debugging by preventing automatic operations when protect modes are enabled

• Fast Forcing

– Permits redirecting any normal interrupt source on the Fast Interrupt of the processor