XIAO nRF54LM20A

Overview

Seeed Studio XIAO nRF54LM20A is a compact, high-performance development board featuring the Nordic nRF54LM20A chip. This SoC integrates an ultra-low power multiprotocol 2.4 GHz radio and an MCU with a 128 MHz Arm(R) Cortex(R)-M33 processor and a RISC-V Fast Lightweight Peripheral Processor (FLPR) coprocessor. It offers 1.5 MB RRAM and 512 KB RAM.

The board features a built-in PMIC (Nordic NPM1300) with battery charging support, an RGB LED, an LSM6DS3TR-C 6-axis IMU, USB HS, NFCT, and an external SPI flash (PY25Q64HA, 64 Mbit). The XIAO form factor provides 28 pins (D0-D27) with support for GPIO, I2C, SPI, UART, ADC, PWM, and more.

Designed for exceptional ultra-low power consumption, it significantly extends battery life. Its robust radio supports Bluetooth(R), Matter, Thread, Zigbee, and a high-throughput 2.4 GHz proprietary mode. The board is ideal for compact, secure, and energy-efficient IoT solutions such as smart wearables, industrial sensors, and advanced human-machine interfaces.

Hardware

128 MHz Arm(R) Cortex(R)-M33 processor
RISC-V FLPR coprocessor for peripheral processing
1.5 MB RRAM (non-volatile memory)
512 KB RAM
Multiprotocol 2.4 GHz radio supporting Bluetooth Low Energy, 802.15.4-2020, and 2.4 GHz proprietary modes
Comprehensive set of peripherals including 14-bit ADC, high-speed serial interfaces, PDM/DMIC, and PWM
Built-in PMIC (Nordic NPM1300) with battery charging
RGB LED (blue, red, green)
LSM6DS3TR-C 6-axis IMU (accelerometer + gyroscope)
USB HS
NFCT (Near Field Communication)
External SPI flash (PY25Q64HA, 64 Mbit)
28-pin XIAO connector (D0-D27)
Advanced security including TrustZone(R) isolation and cryptographic engine protection

For more information about the nRF54LM20A SoC and XIAO nRF54LM20A board, refer to these documents:

Supported Features

The xiao_nrf54lm20a board supports the hardware features listed below.

on-chip / on-board: Feature integrated in the SoC / present on the board.
2 / 2: Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files.
vnd,foo: Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.

`xiao_nrf54lm20a/nrf54lm20a/cpuapp` target

On-target memory for this board target: 511 KiB of RAM, 2036 KiB of Flash.

Type	Location	Description	Compatible
CPU	on-chip	ARM Cortex-M33F CPU1	`arm,cortex-m33f`
ADC	on-chip	Nordic Semiconductor nRF family SAADC node1	`nordic,nrf-saadc`
ARM architecture	on-chip	Nordic UICR (User Information Configuration Registers)1	`nordic,nrf-uicr`
ARM architecture	on-chip	Nordic EGU (Event Generator Unit)2	`nordic,nrf-egu`
Audio	on-chip	Nordic PDM (Pulse Density Modulation interface)2	`nordic,nrf-pdm`
Clock control	on-chip	Generic fixed-rate clock provider4	`fixed-clock`
	on-chip	Nordic nRF low-frequency crystal oscillator (nRF54L series)1	`nordic,nrf54l-lfxo`
	on-chip	Nordic nRF high-frequency crystal oscillator (nRF54L series)1	`nordic,nrf54l-hfxo`
	on-chip	Nordic nRF clock control node1	`nordic,nrf-clock`
Comparator	on-chip	Nordic nRF COMP (analog COMParator)1	`nordic,nrf-comp`
Counter	on-chip	Nordic nRF timer node7	`nordic,nrf-timer`
Debug	on-chip	ARMv8 instrumentation trace macrocell1	`arm,armv8m-itm`
Flash controller	on-chip	Nordic RRAMC (Resistive random access memory controller)1	`nordic,rram-controller`
GPIO & Headers	on-chip	NRF5 GPIO3 1	`nordic,nrf-gpio`
	on-chip	NRF5 GPIOTE2	`nordic,nrf-gpiote`
	on-board	GPIO pins exposed on Seeeduino Xiao (and compatible devices) headers1	`seeed,xiao-gpio`
I2C	on-chip	Nordic nRF family TWIM (TWI master with EasyDMA)2 4	`nordic,nrf-twim`
I2C	on-board	I2C via GPIO bitbanging1	`gpio-i2c`
I2S	on-chip	Nordic TDM (Time division multiplexed audio interface)1	`nordic,nrf-tdm`
IEEE 802.15.4	on-chip	Nordic nRF IEEE 802.15.4 node1	`nordic,nrf-ieee802154`
Input	on-board	Group of GPIO-bound input keys1	`gpio-keys`
Interrupt controller	on-chip	ARMv8-M NVIC (Nested Vectored Interrupt Controller)1	`arm,v8m-nvic`
LED	on-board	Group of GPIO-controlled LEDs1	`gpio-leds`
LED	on-board	Group of PWM-controlled LEDs1	`pwm-leds`
Mailbox	on-chip	Nordic VEVIF (VPR Event Interface) - EVENT RX MODE1	`nordic,nrf-vevif-event-rx`
Mailbox	on-chip	Nordic VEVIF (VPR Event Interface) - TASK TX MODE1	`nordic,nrf-vevif-task-tx`
Multi-Function Device	on-board	Nordic nPM13001	`nordic,npm1300`
Miscellaneous	on-chip	Nordic FICR (Factory Information Configuration Registers)1	`nordic,nrf-ficr`
	on-chip	Nordic DPPIC (Distributed Programmable Peripheral Interconnect Controller)4	`nordic,nrf-dppic`
	on-chip	Nordic PPIB (Programmable Peripheral Interconnect Bridge)8	`nordic,nrf-ppib`
	on-chip	Nordic Memory Privilege Controller (MPC)1	`nordic,nrf-mpc`
MTD	on-board	Properties supporting Zephyr spi-nor flash driver (over the Zephyr SPI API) control of serial flash memories using the standard M25P80-based command set1	`jedec,spi-nor`
MTD	on-chip	Flash node1	`soc-nv-flash`
Networking	on-chip	Nordic nRF family RADIO peripheral1	`nordic,nrf-radio`
Networking	on-chip	Nordic nRF family NFCT (Near Field Communication Tag)1	`nordic,nrf-nfct-v2`
Pin control	on-chip	Nordic nRF family Pin Controller1	`nordic,nrf-pinctrl`
Power management	on-chip	Nordic nRF power control node1	`nordic,nrf-power`
PWM	on-chip	nRF PWM1 2	`nordic,nrf-pwm`
Regulator	on-chip	Nordic REGULATORS (voltage regulators control module) on nRF54L1	`nordic,nrf54l-regulators`
	on-chip	Nordic nRF5X regulator (fixed stage of the core supply)1	`nordic,nrf5x-regulator`
	on-chip	Nordic VBUS regulator for USB peripheral1	`nordic,vregusb-regulator`
	on-board	Nordic nPM1300 PMIC1	`nordic,npm1300-regulator`
	on-board	Fixed voltage regulators1	`regulator-fixed`
Retained memory	on-chip	Nordic GPREGRET (General Purpose Register Retention) device2	`nordic,nrf-gpregret`
RISC-V architecture	on-chip	VPR coprocessor1	`nordic,nrf-vpr-coprocessor`
RNG	on-chip	Nordic nRF CRACEN CTR_DRBG based (Random Number Generator)1	`nordic,nrf-cracen-ctrdrbg`
Sensors	on-chip	Nordic nRF family TEMP node1	`nordic,nrf-temp`
	on-chip	Nordic nRF quadrature decoder (QDEC) node2	`nordic,nrf-qdec`
	on-board	STMicroelectronics LSM6DSL 6-axis accelerometer and gyrometer accessed through I2C bus1	`st,lsm6dsl`
	on-board	NPM1300 PMIC Charger1	`nordic,npm1300-charger`
Serial controller	on-chip	Nordic nRF family UARTE (UART with EasyDMA)2 5	`nordic,nrf-uarte`
SPI	on-chip	Nordic nRF family SPIM (SPI master with EasyDMA)2 5	`nordic,nrf-spim`
SRAM	on-chip	Generic on-chip SRAM1	`mmio-sram`
Timer	on-chip	Nordic GRTC (Global RTC)1	`nordic,nrf-grtc`
Timer	on-chip	ARMv8-M System Tick1	`arm,armv8m-systick`
USB	on-chip	Nordic wrapper for USB controller and PHY hardware1	`nordic,nrf-usbhs-wrapper`
	on-chip	DesignWare OTG USB 2.0 controller1	`snps,dwc2`
	on-chip	Nordic USB PD Charging-Type Detector1	`nordic,nrf-usbhs-bc12`
Watchdog	on-chip	Nordic nRF family WDT (Watchdog Timer)2	`nordic,nrf-wdt`

Connections and IOs

In the following table, the column Name contains Pin names. For example, P1_0 means Pin number 0 on PORT1, as used in the board’s datasheets and manuals.

Name	Function	Usage
P1_22	GPIO	LED0 (Blue)
P1_23	GPIO	LED1 (Red)
P1_24	GPIO	LED2 (Green)
P0_9	GPIO	Button 0
P1_11	USART20_TX	UART Console TX
P1_10	USART20_RX	UART Console RX
P1_8	USART21_TX	XIAO Serial TX
P1_9	USART21_RX	XIAO Serial RX
P1_3	TWIM22_SDA	XIAO I2C SDA
P1_7	TWIM22_SCL	XIAO I2C SCL
P1_4	SPIM23_SCK	XIAO SPI SCK
P1_6	SPIM23_MOSI	XIAO SPI MOSI
P1_5	SPIM23_MISO	XIAO SPI MISO
P0_8	TWIM30_SDA	IMU I2C SDA
P0_7	TWIM30_SCL	IMU I2C SCL
P1_0	GPIO	XIAO D0
P1_31	GPIO	XIAO D1
P1_30	GPIO	XIAO D2
P1_29	GPIO	XIAO D3
P1_3	GPIO	XIAO D4
P1_7	GPIO	XIAO D5
P1_8	GPIO	XIAO D6
P1_9	GPIO	XIAO D7
P1_4	GPIO	XIAO D8
P1_5	GPIO	XIAO D9
P1_6	GPIO	XIAO D10
P1_12	GPIO	Power Enable
P1_15	GPIO	PMIC I2C SDA
P1_16	GPIO	PMIC I2C SCL
P1_13	PDM20_CLK	DMIC Clock
P1_14	PDM20_DIN	DMIC Data
P2_1	SPIM00_SCK	External SPI Flash SCK
P2_2	SPIM00_MOSI	External SPI Flash MOSI
P2_4	SPIM00_MISO	External SPI Flash MISO

Programming and Debugging

The xiao_nrf54lm20a board supports the runners and associated west commands listed below.

	flash	debug	debugserver	rtt	attach	reset
jlink	✅	✅	✅	✅	✅	✅
nrfutil	✅
openocd	✅ (default)	✅ (default)	✅	✅	✅

The XIAO nRF54LM20A contains a SAMD11 with CMSIS-DAP, allowing flashing, debugging, logging, etc. over the USB port.

Flashing

Connect the XIAO nRF54LM20A board to your host computer using the USB port. A USB CDC ACM serial port should appear on the host, that can be used to view logs from the flashed application.

Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b xiao_nrf54lm20a/nrf54lm20a/cpuapp samples/hello_world
west flash

Open a serial terminal (minicom, putty, etc.) connecting to the USB CDC ACM serial port.

Reset the board and you should see the following message in the terminal:

Hello World! xiao_nrf54lm20a/nrf54lm20a/cpuapp