SAM7X256_14 Datasheet, PDF (145/662 Pages) ATMEL Corporation – ARM-based Flash MCU

23.6 Product Dependencies
23.6.1 I/O Lines
The interrupt signals FIQ and IRQ0 to IRQn are normally multiplexed through the PIO controllers. Depending on the
features of the PIO controller used in the product, the pins must be programmed in accordance with their assigned
interrupt function. This is not applicable when the PIO controller used in the product is transparent on the input path.
23.6.2 Power Management
The Advanced Interrupt Controller is continuously clocked. The Power Management Controller has no effect on the
Advanced Interrupt Controller behavior.
The assertion of the Advanced Interrupt Controller outputs, either nIRQ or nFIQ, wakes up the ARM processor while it is
in Idle Mode. The General Interrupt Mask feature enables the AIC to wake up the processor without asserting the
interrupt line of the processor, thus providing synchronization of the processor on an event.
23.6.3 Interrupt Sources
The Interrupt Source 0 is always located at FIQ. If the product does not feature an FIQ pin, the Interrupt Source 0 cannot
be used.
The Interrupt Source 1 is always located at System Interrupt. This is the result of the OR-wiring of the system peripheral
interrupt lines, such as the System Timer, the Real Time Clock, the Power Management Controller and the Memory
Controller. When a system interrupt occurs, the service routine must first distinguish the cause of the interrupt. This is
performed by reading successively the status registers of the above mentioned system peripherals.
The interrupt sources 2 to 31 can either be connected to the interrupt outputs of an embedded user peripheral or to
external interrupt lines. The external interrupt lines can be connected directly, or through the PIO Controller.
The PIO Controllers are considered as user peripherals in the scope of interrupt handling. Accordingly, the PIO
Controller interrupt lines are connected to the Interrupt Sources 2 to 31.
The peripheral identification defined at the product level corresponds to the interrupt source number (as well as the bit
number controlling the clock of the peripheral). Consequently, to simplify the description of the functional operations and
the user interface, the interrupt sources are named FIQ, SYS, and PID2 to PID31.
SAM7X Series [DATASHEET]
6120K–ATARM–11-Feb-14
145