4
42023G–SAM–03/2014
ATSAM4L8/L4/L2
events, even in sleep modes where the module clock is stopped. Power monitoring is supported
by on-chip Power-on Reset (POR18, POR33), Brown-out Detectors (BOD18, BOD33). The
device features several oscillators, such as Phase Locked Loop (PLL), Digital Frequency
Locked Loop (DFLL), Oscillator 0 (OSC0), Internal RC 4,8,12MHz oscillator (RCFAST), system
RC oscillator (RCSYS), Internal RC 80MHz, Internal 32kHz RC and 32kHz Crystal Oscillator.
Either of these oscillators can be used as source for the system clock. The DFLL is a program-
mable internal oscillator from 40 to 150MHz. It can be tuned to a high accuracy if an accurate
reference clock is running, e.g. the 32kHz crystal oscillator.
The Watchdog Timer (WDT) will reset the device unless it is periodically serviced by the soft-
ware. This allows the device to recover from a condition that has caused the system to be
unstable.
The Asynchronous Timer (AST) combined with the 32 kHz crystal oscillator supports powerful
real-time clock capabilities, with a maximum timeout of up to 136 years. The AST can operate in
counter or calendar mode.
The Frequency Meter (FREQM) allows accurate measuring of a clock frequency by comparing it
to a known reference clock.
The Full-speed USB 2.0 device and embedded host interface (USBC) supports several USB
classes at the same time utilizing the rich end-point configuration.
The device includes six identical 16-bit Timer/Counter (TC) channels. Each channel can be inde-
pendently programmed to perform frequency measurement, event counting, interval
measurement, pulse generation, delay timing, and pulse width modulation.
The ATSAM4L8/L4/L2 also features many communication interfaces, like USART, SPI, or TWI,
for communication intensive applications. The USART supports different communication modes,
like SPI Mode and LIN Mode.
A general purpose 16-channel ADC is provided, as well as four analog comparators (ACIFC).
The ADC can operate in 12-bit mode at full speed. The analog comparators can be paired to
detect when the sensing voltage is within or outside the defined reference window.
Atmel offers the QTouch Library for embedding capacitive touch buttons, sliders, and wheels
functionality. The patented charge-transfer signal acquisition offers robust sensing and includes
fully debounced reporting of touch keys as well as Adjacent Key Suppression (AKS) technol-
ogy for unambiguous detection of key events. The easy-to-use QTouch Suite toolchain allows
you to explore, develop, and debug your own touch applications.
The Audio Bitstream DAC (ABDACB) converts a 16-bit sample value to a digital bitstream with
an average value proportional to the sample value. Two channels are supported, making the
ABDAC particularly suitable for stereo audio.
The Inter-IC Sound Controller (IISC) provides a 5-bit wide, bidirectional, synchronous, digital
audio link with external audio devices. The controller is compliant with the Inter-IC Sound (I2S)
bus specification.