AT91R40008 Datasheet, PDF (12/18 Pages) ATMEL Corporation – AT91 ARM Thumb Microcontroller

System Peripherals
PS: Power-saving
AIC: Advanced Interrupt
Controller
PIO: Parallel I/O Controller
WD: Watchdog
SF: Special Function
The Power-saving feature optimizes power consumption, enabling the software to stop
the ARM7TDMI clock (Idle mode), restarting it when the module receives an interrupt (or
reset). It also enables on-chip peripheral clocks to be enabled and disabled individually,
matching power consumption and application need.
The Advanced Interrupt Controller has an 8-level priority, individually maskable, vec-
tored interrupt controller, and drives the NIRQ and NFIQ pins of the ARM7TDMI from:
• The external fast interrupt line (FIQ)
• The three external interrupt request lines (IRQ0 - IRQ2)
• The interrupt signals from the on-chip peripherals
The AIC is extensively programmable offering maximum flexibility, and its vectoring fea-
tures reduce the real-time overhead in handling interrupts.
The AIC also features a spurious vector, which reduces spurious interrupt handling to a
minimum, and a protect mode that facilitates the debug capabilities.
The AT91R40008 microcontroller has 32 programmable I/O lines. Six pins are dedi-
cated as general-purpose I/O pins. Other I/O lines are multiplexed with an external
signal of a peripheral to optimize the use of available package pins. The PIO controller
enables generation of an interrupt on input change on any of the PIO pins.
The Watchdog is built around a 16-bit counter and is used to prevent system lock-up if
the software becomes trapped in a deadlock. It can generate an internal reset or inter-
rupt, or assert an active level on the dedicated pin NWDOVF. All programming registers
are password-protected to prevent unintentional programming.
The AT91R40008 microcontroller provides registers that implement the following special
functions:
• Chip identification
• RESET status
• Protect mode
12 _{AT91R40008 - Summary}
1732DS–ATARM–03/04