AT91SAM9261_08 Datasheet, PDF (34/43 Pages) ATMEL Corporation – AT91 ARM Thumb-based Microcontrollers

10.3.5
System Interrupt
The System Interrupt in Source 1 is the wired-OR of the interrupt signals coming from:
• the SDRAM Controller
• the Debug Unit
• the Periodic Interval Timer
• the Real-Time Timer
• the Watchdog Timer
• the Reset Controller
• the Power Management Controller
The clock of these peripherals cannot be deactivated and Peripheral ID 1 can only be used
within the Advanced Interrupt Controller.
10.3.6
External Interrupts
All external interrupt signals, i.e., the Fast Interrupt signal FIQ or the Interrupt signals IRQ0 to
IRQ2, use a dedicated Peripheral ID. However, there is no clock control associated with these
peripheral IDs.
10.4
External Bus Interface
• Integrates two External Memory Controllers:
– Static Memory Controller
– SDRAM Controller
• Additional logic for NAND Flash and CompactFlash support
– NAND Flash support: 8-bit as well as 16-bit devices are supported
– CompactFlash support: all modes (Attribute Memory, Common Memory, I/O, True
IDE) are supported but the signals -IOIS16 (I/O and True IDE modes) and -ATA SEL
(True IDE mode) are not handled.
• Optimized External Bus
– 16- or 32-bit Data Bus
– Up to 26-bit Address Bus, up to 64 Mbytes addressable
– Eight Chip Selects, each reserved to one of the eight Memory Areas
– Optimized pin multiplexing to reduce latencies on External Memories
• Configurable Chip Select Assignment Managed by EBI_CSA Register located in the MATRIX
user interface
– Static Memory Controller on NCS0
– SDRAM Controller or Static Memory Controller on NCS1
– Static Memory Controller on NCS2
– Static Memory Controller on NCS3, Optional NAND Flash Support
– Static Memory Controller on NCS4 - NCS5, Optional CompactFlash Support
– Static Memory Controller on NCS6 - NCS7
34 AT91SAM9261 Preliminary
6062JS–ATARM–06-Feb-08