AT91M40807 ATMEL Corporation, AT91M40807 Datasheet - Page 12

• Manufacturer Part Number: AT91M40807
• Description: At91 Arm(r) Thumb(r) Microcontroller
• Manufacturer: ATMEL Corporation

System Peripherals
PS: Power-saving
AIC: Advanced Interrupt
Controller
PIO: Parallel I/O Controller
WD: Watchdog
SF: Special Function
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AT91M40807
The power-saving feature of the AT91M40807 microcontroller optimizes power con-
sumption, enabling the software to stop the ARM7TDMI clock (idle mode) and 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 appli-
cation 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:
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The AIC is largely programmable, offering maximum flexibility, and its vectoring features
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 AT91M40807 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 and insertion of a simple input glitch
filter 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 AT91M40807 microcontroller provides registers that implement the following spe-
cial functions.
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The external fast interrupt line (FIQ)
The three external interrupt request lines (IRQ0-IRQ2)
The interrupt signals from the on-chip peripherals
Chip Identification
RESET Status
Protect Mode
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