at91sam9g45 ATMEL Corporation, at91sam9g45 Datasheet - Page 39

• Manufacturer Part Number: at91sam9g45
• Description: At91 Arm Thumb-based Microcontrollers
• Manufacturer: ATMEL Corporation

9.3
9.3.1
9.3.2
9.4
6438CS–ATARM–13-Oct-09
Peripheral Interrupts and Clock Control
Peripheral Signals Multiplexing on I/O Lines
System Interrupt
External Interrupts
The System Interrupt in Source 1 is the wired-OR of the interrupt signals coming from:
The clock of these peripherals cannot be deactivated and Peripheral ID 1 can only be used
within the Advanced Interrupt Controller.
All external interrupt signals, i.e., the Fast Interrupt signal FIQ or the Interrupt signal IRQ, use a
dedicated Peripheral ID. However, there is no clock control associated with these peripheral IDs.
The AT91SAM9G45 features 5 PIO controllers, PIOA, PIOB, PIOC, PIOD and PIOE, which mul-
tiplexes the I/O lines of the peripheral set.
Each PIO Controller controls up to 32 lines. Each line can be assigned to one of two peripheral
functions, A or B. The multiplexing tables in the following paragraphs define how the I/O lines of
the peripherals A and B are multiplexed on the PIO Controllers. The two columns “Function” and
“Comments” have been inserted in this table for the user’s own comments; they may be used to
track how pins are defined in an application.
Note that some peripheral function which are output only, might be duplicated within the both
tables.
The column “Reset State” indicates whether the PIO Line resets in I/O mode or in peripheral
mode. If I/O is mentioned, the PIO Line resets in input with the pull-up enabled, so that the
device is maintained in a static state as soon as the reset is released. As a result, the bit corre-
sponding to the PIO Line in the register PIO_PSR (Peripheral Status Register) resets low.
If a signal name is mentioned in the “Reset State” column, the PIO Line is assigned to this func-
tion and the corresponding bit in PIO_PSR resets high. This is the case of pins controlling
memories, in particular the address lines, which require the pin to be driven as soon as the reset
is released. Note that the pull-up resistor is also enabled in this case.
To amend EMC, programmable delay has been inserted on PIO lines able to run at high speed.
• the DDR2/LPDDR Controller
• the Debug Unit
• the Periodic Interval Timer
• the Real-Time Timer
• the Real-Time Clock
• the Watchdog Timer
• the Reset Controller
• the Power Management Controller
AT91SAM9G45
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