Datasheet

SAM9263 [DATASHEET]
Atmel-6249N-ATARM-SAM9263-Datasheet_14-Mar-16
430
30.4.10 Input Change Interrupt
The PIO Controller can be programmed to generate an interrupt when it detects an input change on an I/O line.
The Input Change Interrupt is controlled by writing PIO_IER (Interrupt Enable Register) and PIO_IDR (Interrupt
Disable Register), which respectively enable and disable the input change interrupt by setting and clearing the
corresponding bit in PIO_IMR (Interrupt Mask Register). As Input change detection is possible only by comparing
two successive samplings of the input of the I/O line, the PIO Controller clock must be enabled. The Input Change
Interrupt is available, regardless of the configuration of the I/O line, i.e. configured as an input only, controlled by
the PIO Controller or assigned to a peripheral function.
When an input change is detected on an I/O line, the corresponding bit in PIO_ISR (Interrupt Status Register) is
set. If the corresponding bit in PIO_IMR is set, the PIO Controller interrupt line is asserted. The interrupt signals of
the thirty-two channels are ORed-wired together to generate a single interrupt signal to the Advanced Interrupt
Controller.
When the software reads PIO_ISR, all the interrupts are automatically cleared. This signifies that all the interrupts
that are pending when PIO_ISR is read must be handled.
Figure 30-6. Input Change Interrupt Timings
MCK
Pin Level
Read PIO_ISR
APB Access
PIO_ISR
APB Access