Datasheet
1. Description
The SAM D21 is a series of low-power microcontrollers using the 32-bit ARM
®
Cortex
®
-M0+ processor,
and ranging from 32-pins to 64-pins with up to 256 KB Flash and 32 KB of SRAM. The SAM D21 operate
at a maximum frequency of 48 MHz and reach 2.46 CoreMark/MHz. They are designed for simple and
intuitive migration with identical peripheral modules, hex compatible code, identical linear address map,
and pin compatible migration paths between all devices in the product series. All devices include
intelligent and flexible peripherals, Event System for inter-peripheral signaling, and support for capacitive
touch button, slider, and wheel user interfaces.
The SAM D21 provide the following features: In-system programmable Flash, 12-channel Direct Memory
Access Controller (DMAC), 12-channel Event System, programmable Interrupt Controller, up to 52
programmable I/O pins, 32-bit Real-Time Clock and Calendar (RTC), up to five 16-bit Timer/Counters
(TC) and up to four 24-bit Timer/Counters for Control (TCC), where each TC can be configured to perform
frequency and waveform generation, accurate program execution timing or input capture with time and
frequency measurement of digital signals. The TCs can operate in 8- or 16-bit mode, selected TCs can
be cascaded to form a 32-bit TC, and three timer/counters have extended functions optimized for motor,
lighting, and other control applications. The series provide one full-speed USB 2.0 embedded host and
device interface; up to six Serial Communication Modules (SERCOM) that each can be configured to act
as an USART, UART, SPI, I
2
C up to 3.4MHz, SMBus, PMBus, and LIN slave; two-channel I
2
S interface;
up to twenty-channel 350 ksps 12-bit ADC with programmable gain and optional oversampling and
decimation supporting up to 16-bit resolution, one 10-bit 350 ksps DAC, up to four analog comparators
with Window mode, Peripheral Touch Controller (PTG) supporting up to 256 buttons, sliders, wheels, and
proximity sensing; programmable Watchdog Timer (WDT), brown-out detector and power-on Reset and
two-pin Serial Wire Debug (SWD) program and debug interface.
All devices have accurate and low-power external and internal oscillators. All oscillators can be used as a
source for the system clock. Different clock domains can be independently configured to run at different
frequencies, enabling power saving by running each peripheral at its optimal clock frequency, and thus
maintaining a high CPU frequency while reducing power consumption.
The SAM D21 have two software-selectable sleep modes, Idle and Stand-by. In Idle mode, the CPU is
stopped while all other functions can be kept running. In Stand-by mode, all clocks and functions are
stopped, expect those selected to continue running. The device supports SleepWalking. This feature
allows the peripheral to wake up from sleep based on predefined conditions, and thus allows the CPU to
wake up only when needed, e.g., when a threshold is crossed or a result is ready. The Event System
supports synchronous and asynchronous events, allowing peripherals to receive, react to and send
events even in Stand-by mode.
The Flash program memory can be reprogrammed in-system through the SWD interface. The same
interface can be used for non-intrusive on-chip debug of application code. A boot loader running in the
device can use any communication interface to download and upgrade the application program in the
Flash memory.
The SAM D21 microcontrollers are supported with a full suite of program and system development tools,
including C compilers, macro assemblers, program debugger/simulators, programmers, and evaluation
kits.
SAM D21 Family
Description
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001882D-page 12