AT91FR4042 ATMEL Corporation, AT91FR4042 Datasheet - Page 16

• Manufacturer Part Number: AT91FR4042
• Description: The AT91FR4042 Features 256K Bytes of On-chip SRAM, 512K Bytes of Flash, an External Bus Interface, a 3-channel Timer/Counter, 2 Usarts, a Watchdog Timer And Advanced Power-saving Features.
• 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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AT91FR4042
Preliminary
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 needs.
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 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 detection feature, which reduces spurious inter-
rupt handling to a minimum, and a protect mode that facilitates the debug capabilities.
The AT91FR4042 has 32 programmable I/O lines. Six pins are dedicated 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 AT91FR4042 provides registers that implement the following special 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
2648B–ATARM–12/02