Atmel Xplained Pro Evaluation Kit ATSAMD20-XPRO ATSAMD20-XPRO Data Sheet

Product codes
ATSAMD20-XPRO
Page of 660
128
Atmel | SMART SAM D20 [DATASHEET]
Atmel-42129K–SAM-D20_datasheet–06/2014
16.
 SYSCTRL – System Controller
16.1
Overview
The System Controller (SYSCTRL) provides a user interface to the clock sources, brown out detectors, on-chip voltage 
regulator and voltage reference of the device.
Through the interface registers, it is possible to enable, disable, calibrate and monitor the SYSCTRL sub-peripherals.
All sub-peripheral statuses are collected in the Power and Clocks Status register (PCLKSR - refer to 
additionally trigger interrupts upon status changes via the INTENSET (
INTFLAG (
) registers.
Additionally, BOD33 interrupts can be used to wake up the device from standby mode upon a programmed brown-out 
detection.
16.2
Features
z
0.4-32MHz Crystal Oscillator (XOSC)
z
Tunable gain control
z
Programmable start-up time
z
Crystal or external input clock on XIN I/O
z
32.768kHz Crystal Oscillator (XOSC32K)
z
Automatic or manual gain control
z
Programmable start-up time
z
Crystal or external input clock on XIN32 I/O
z
32.768kHz High Accuracy Internal Oscillator (OSC32K)
z
Frequency fine tuning
z
Programmable start-up time
z
32.768kHz Ultra Low Power Internal Oscillator (OSCULP32K)
z
Ultra low power, always-on oscillator
z
Frequency fine tuning
z
Calibration value loaded from Flash Factory Calibration at reset
z
8MHz Internal Oscillator (OSC8M)
z
Fast startup
z
Output frequency fine tuning
z
4/2/1MHz divided output frequencies available
z
Calibration value loaded from Flash Factory Calibration at reset
z
Digital Frequency Locked Loop (DFLL48M)
z
Internal
 
oscillator with no external components
z
48MHz output frequency
z
Operates standalone as a high-frequency programmable oscillator in open loop mode
z
Operates as an accurate frequency multiplier against a known frequency in closed loop mode
z
3.3V Brown-Out Detector (BOD33)
z
Programmable threshold
z
Threshold value loaded from Flash User Calibration at startup
z
Triggers resets or interrupts
z
Operating modes:
z
Continuous mode
z
Sampled mode for low power applications (programmable refresh frequency)
z
Hysteresis
z
Voltage Reference System (VREF)
z
Bandgap voltage generator with programmable calibration value
z
Temperature sensor
z
Bandgap calibration value loaded from Flash Factory Calibration at startup