Datasheet

395
11011B–ATARM–21-Feb-12
SAM3N
395
11011B–ATARM–21-Feb-12
SAM3N
26.5.10.2 Interrupt Mode Configuration
All the interrupt sources are enabled by writing 32’hFFFF_FFFF in PIO_IER.
Then the Additional Interrupt Mode is enabled for line 0 to 7 by writing 32’h0000_00FF in
PIO_AIMER.
26.5.10.3 Edge or Level Detection Configuration
Lines 3, 4 and 5 are configured in Level detection by writing 32’h0000_0038 in PIO_LSR.
The other lines are configured in Edge detection by default, if they have not been previously con-
figured. Otherwise, lines 0, 1, 2, 6 and 7 must be configured in Edge detection by writing
32’h0000_00C7 in PIO_ESR.
26.5.10.4 Falling/Rising Edge or Low/High Level Detection Configuration.
Lines 0, 2, 4, 5 and 7 are configured in Rising Edge or High Level detection by writing
32’h0000_00B5 in PIO_REHLSR.
The other lines are configured in Falling Edge or Low Level detection by default, if they have not
been previously configured. Otherwise, lines 1, 3 and 6 must be configured in Falling Edge/Low
Level detection by writing 32’h0000_004A in PIO_FELLSR.
Figure 26-8. Input Change Interrupt Timings if there are no Additional Interrupt Modes
26.5.11 I/O Lines Lock
When an I/O line is controlled by a peripheral (particularly the Pulse Width Modulation Controller
PWM), it can become locked by the action of this peripheral via an input of the PIO controller.
When an I/O line is locked, the write of the corresponding bit in the registers PIO_PER,
PIO_PDR, PIO_MDER, PIO_MDDR, PIO_PUDR, PIO_PUER, PIO_ABCDSR1 and
PIO_ABCDSR2 is discarded in order to lock its configuration. The user can know at anytime
which I/O line is locked by reading the PIO Lock Status register PIO_LOCKSR. Once an I/O line
is locked, the only way to unlock it is to apply a hardware reset to the PIO Controller.
26.5.12 Programmable Schmitt Trigger
It is possible to configure each input for the Schmitt Trigger. By default the Schmitt trigger is
active. Disabling the Schmitt Trigger is requested when using the QTouch
™
Library.
MCK
Pin Level
Read PIO_ISR
APB Access
PIO_ISR
APB Access