FRDM-MCXE31B

Overview

The FRDM-MCXE31B board is a design and evaluation platform based on the NXP MCXE31B microcontroller (MCU). NXP MCXE31B MCU based on an Arm Cortex-M7 core, running at speeds of up to 160 MHz with a 2.97 to 5.5V supply.

Hardware

MCXE31B Arm Cortex-M7 microcontroller running up to 160 MHz
4MB dual-bank on chip Flash
320KB SRAM + 192KB TCM
2x I2C
6x SPI
16x UART
On-board MCU-Link debugger with CMSIS-DAP
Arduino Header, mikroBUS

For more information about the MCXE31B SoC and FRDM-MCXE31B board, see:

Supported Features

The frdm_mcxe31b 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.

`frdm_mcxe31b@default/mcxe31b` target

On-target memory for this board target: 288 KiB of RAM, 3920 KiB of Flash.

Type	Location	Description	Compatible
CPU	on-chip	ARM Cortex-M7 CPU1	`arm,cortex-m7`
ADC	on-chip	NXP successive-approximation ADC (SAR ADC) controller1 2	`nxp,sar-adc`
CAN	on-chip	NXP FlexCAN CANFD controller1 5	`nxp,flexcan-fd`
Clock control	on-chip	Fast internal RC oscillator1	`nxp,firc`
	on-chip	Fast external crystal oscillator1	`nxp,fxosc`
	on-chip	Glitchless clock switching Clock Generation module1	`nxp,mc-cgm`
	on-chip	Phase-locked loop1	`nxp,plldig`
Clock monitor	on-chip	NXP Clock Monitoring Unit - Frequency Check (CMU_FC)4	`nxp,cmu-fc`
Clock monitor	on-chip	NXP Clock Monitoring Unit - Frequency Meter (CMU_FM)2	`nxp,cmu-fm`
Comparator	on-chip	NXP Low Power Comparator (LPCMP)3	`nxp,lpcmp`
Counter	on-chip	NXP Periodic Interrupt Timer (PIT)1 2	`nxp,pit`
	on-chip	Child node for the Periodic Interrupt Timer node, intended for an individual timer channel12	`nxp,pit-channel`
	on-chip	NXP System Timer Module (STM)1 1	`nxp,stm`
CRC	on-chip	NXP CRC device1	`nxp,crc`
DMA	on-chip	NXP MCUX EDMA controller1	`nxp,mcux-edma`
EDAC	on-chip	NXP Error Injection Module1	`nxp,eim`
EDAC	on-chip	NXP Error Reporting Module1	`nxp,erm`
Ethernet	on-chip	NXP ENET QOS Ethernet Controller1	`nxp,enet-qos`
	on-chip	Synopsys DesignWare MAC MDIO controller1	`snps,dwmac-mdio`
	on-board	Generic MII PHY1	`ethernet-phy`
	on-chip	Synopsys DesignWare MAC PTP (Precision Time Protocol) Clock1	`snps,dwmac-ptp-clock`
Flash controller	on-chip	NXP C40 Flash Controller1	`nxp,c40-flash-controller`
GPIO & Headers	on-chip	NXP SIUL2 GPIO controller5 9	`nxp,siul2-gpio`
	on-board	GPIO pins exposed on Arduino Uno (R3) headers1	`arduino-header-r3`
	on-board	GPIO pins exposed on NXP LCD 8080 interface (e.g., used on LCD-PAR-035 panel)1	`nxp,lcd-8080`
Hardware information	on-chip	NXP MC_RGM (Reset Generation Module)1	`nxp,mc-rgm`
Hardware information	on-chip	NXP OTP unique chip identifier (UID)1	`nxp,otp-uid`
Hardware spinlock	on-chip	NXP SEMA42 hardware semaphore controller1	`nxp,sema42`
I2C	on-chip	NXP LPI2C controller2	`nxp,lpi2c`
I2S	on-chip	NXP mcux SAI-I2S controller1 1	`nxp,mcux-i2s`
Input	on-board	Group of GPIO-bound input keys1	`gpio-keys`
Interrupt controller	on-chip	NXP SIUL2 External Interrupts Request controller1	`nxp,siul2-eirq`
	on-chip	NXP S32 Wake-up Unit1	`nxp,s32-wkpu`
	on-chip	ARMv7-M NVIC (Nested Vectored Interrupt Controller)1	`arm,v7m-nvic`
LED	on-board	Group of GPIO-controlled LEDs1	`gpio-leds`
MIPI-DBI	on-board	NXP FlexIO LCD controller1	`nxp,mipi-dbi-flexio-lcdif`
Miscellaneous	on-chip	NXP FlexIO controller1	`nxp,flexio`
Multi-bit SPI	on-chip	NXP QSPI controller with MSPI interface1	`nxp,qspi`
MTD	on-board	Generic NOR flash on MSPI bus1	`jedec,nor`
MTD	on-chip	NXP C40 Internal Flash1	`nxp,c40-flash`
MUX	on-chip	NXP TRGMUX peripheral wrapper1	`nxp,trgmux`
Pin control	on-chip	NXP SIUL2 Pin Controller for MCXE31X SoCs1	`nxp,mcxe31x-siul2-pinctrl`
PWM	on-chip	Enhanced Modular IO SubSystem (eMIOS)1 2	`nxp,emios`
PWM	on-chip	NXP eMIOS PWM node1 2	`nxp,emios-pwm`
RTC	on-chip	NXP Real Time Clock (RTC) — JDP-generation RTC IP1	`nxp,rtc-jdp`
Sensors	on-board	FXLS8974 3-axis accelerometer sensor1	`nxp,fxls8974`
Sensors	on-chip	NXP on-die temperature sensor (TEMPSENSE)1	`nxp,tempsense`
Serial controller	on-chip	NXP LPUART1 15	`nxp,lpuart`
SPI	on-chip	NXP LPSPI controller1 5	`nxp,lpspi`
SRAM	on-chip	Generic on-chip SRAM2	`mmio-sram`
Timer	on-chip	ARMv7-M System Tick1	`arm,armv7m-systick`
Watchdog	on-chip	Software Watchdog Timer (SWT)1	`nxp,s32-swt`

`frdm_mcxe31b@w25q64/mcxe31b` target

On-target memory for this board target: 288 KiB of RAM, 3920 KiB of Flash.

Type	Location	Description	Compatible
CPU	on-chip	ARM Cortex-M7 CPU1	`arm,cortex-m7`
ADC	on-chip	NXP successive-approximation ADC (SAR ADC) controller1 2	`nxp,sar-adc`
CAN	on-chip	NXP FlexCAN CANFD controller1 5	`nxp,flexcan-fd`
Clock control	on-chip	Fast internal RC oscillator1	`nxp,firc`
	on-chip	Fast external crystal oscillator1	`nxp,fxosc`
	on-chip	Glitchless clock switching Clock Generation module1	`nxp,mc-cgm`
	on-chip	Phase-locked loop1	`nxp,plldig`
Clock monitor	on-chip	NXP Clock Monitoring Unit - Frequency Check (CMU_FC)4	`nxp,cmu-fc`
Clock monitor	on-chip	NXP Clock Monitoring Unit - Frequency Meter (CMU_FM)2	`nxp,cmu-fm`
Comparator	on-chip	NXP Low Power Comparator (LPCMP)3	`nxp,lpcmp`
Counter	on-chip	NXP Periodic Interrupt Timer (PIT)1 2	`nxp,pit`
	on-chip	Child node for the Periodic Interrupt Timer node, intended for an individual timer channel12	`nxp,pit-channel`
	on-chip	NXP System Timer Module (STM)1 1	`nxp,stm`
CRC	on-chip	NXP CRC device1	`nxp,crc`
DMA	on-chip	NXP MCUX EDMA controller1	`nxp,mcux-edma`
EDAC	on-chip	NXP Error Injection Module1	`nxp,eim`
EDAC	on-chip	NXP Error Reporting Module1	`nxp,erm`
Ethernet	on-chip	NXP ENET QOS Ethernet Controller1	`nxp,enet-qos`
	on-chip	Synopsys DesignWare MAC MDIO controller1	`snps,dwmac-mdio`
	on-board	Generic MII PHY1	`ethernet-phy`
	on-chip	Synopsys DesignWare MAC PTP (Precision Time Protocol) Clock1	`snps,dwmac-ptp-clock`
Flash controller	on-chip	NXP C40 Flash Controller1	`nxp,c40-flash-controller`
GPIO & Headers	on-chip	NXP SIUL2 GPIO controller5 9	`nxp,siul2-gpio`
	on-board	GPIO pins exposed on Arduino Uno (R3) headers1	`arduino-header-r3`
	on-board	GPIO pins exposed on NXP LCD 8080 interface (e.g., used on LCD-PAR-035 panel)1	`nxp,lcd-8080`
Hardware information	on-chip	NXP MC_RGM (Reset Generation Module)1	`nxp,mc-rgm`
Hardware information	on-chip	NXP OTP unique chip identifier (UID)1	`nxp,otp-uid`
Hardware spinlock	on-chip	NXP SEMA42 hardware semaphore controller1	`nxp,sema42`
I2C	on-chip	NXP LPI2C controller2	`nxp,lpi2c`
I2S	on-chip	NXP mcux SAI-I2S controller1 1	`nxp,mcux-i2s`
Input	on-board	Group of GPIO-bound input keys1	`gpio-keys`
Interrupt controller	on-chip	NXP SIUL2 External Interrupts Request controller1	`nxp,siul2-eirq`
	on-chip	NXP S32 Wake-up Unit1	`nxp,s32-wkpu`
	on-chip	ARMv7-M NVIC (Nested Vectored Interrupt Controller)1	`arm,v7m-nvic`
LED	on-board	Group of GPIO-controlled LEDs1	`gpio-leds`
MIPI-DBI	on-board	NXP FlexIO LCD controller1	`nxp,mipi-dbi-flexio-lcdif`
Miscellaneous	on-chip	NXP FlexIO controller1	`nxp,flexio`
Multi-bit SPI	on-chip	NXP QSPI controller with MSPI interface1	`nxp,qspi`
MTD	on-board	Generic NOR flash on MSPI bus1	`jedec,nor`
MTD	on-chip	NXP C40 Internal Flash1	`nxp,c40-flash`
MUX	on-chip	NXP TRGMUX peripheral wrapper1	`nxp,trgmux`
Pin control	on-chip	NXP SIUL2 Pin Controller for MCXE31X SoCs1	`nxp,mcxe31x-siul2-pinctrl`
PWM	on-chip	Enhanced Modular IO SubSystem (eMIOS)1 2	`nxp,emios`
PWM	on-chip	NXP eMIOS PWM node1 2	`nxp,emios-pwm`
RTC	on-chip	NXP Real Time Clock (RTC) — JDP-generation RTC IP1	`nxp,rtc-jdp`
Sensors	on-board	FXLS8974 3-axis accelerometer sensor1	`nxp,fxls8974`
Sensors	on-chip	NXP on-die temperature sensor (TEMPSENSE)1	`nxp,tempsense`
Serial controller	on-chip	NXP LPUART1 15	`nxp,lpuart`
SPI	on-chip	NXP LPSPI controller1 5	`nxp,lpspi`
SRAM	on-chip	Generic on-chip SRAM2	`mmio-sram`
Timer	on-chip	ARMv7-M System Tick1	`arm,armv7m-systick`
Watchdog	on-chip	Software Watchdog Timer (SWT)1	`nxp,s32-swt`

Shields for Supported Features

Some features in the table above are tested with Zephyr shields. These shields are tested on this board:

NXP LCD_PAR_S035 TFT LCD Module - supports the Display interface. This board uses the MIPI_DBI interface of the shield, connected to the FlexIO on-chip peripheral.

Connections and IOs

Each GPIO port is divided into two banks: low bank, from pin 0 to 15, and high bank, from pin 16 to 31. For example, PTA2 is the pin 2 of gpioa_l (low bank), and PTA20 is the pin 4 of gpioa_h (high bank).

The GPIO controller provides the option to route external input pad interrupts to either the SIUL2 EIRQ or WKPU interrupt controllers, as supported by the SoC. By default, GPIO interrupts are routed to SIUL2 EIRQ interrupt controller, unless they are explicitly configured to be directed to the WKPU interrupt controller, as outlined in dts/bindings/gpio/nxp,siul2-gpio.yaml.

To find information about which GPIOs are compatible with each interrupt controller, refer to the device reference manual.

Name	Function	Usage
PTC16	GPIO	Red LED
PTB22	GPIO	Green LED
PTC14	GPIO	Blue LED
PTE3	LPUART5_RX	UART Console
PTE14	LPUART5_TX	UART Console
PTA7	FLEXCAN0	CAN0 TX
PTA6	FLEXCAN0	CAN0 RX
PTB4	EMAC	Ethernet MDIO
PTB5	EMAC	Ethernet MDC
PTC0	EMAC	Ethernet RMII RXD1
PTC1	EMAC	Ethernet RMII RXD0
PTC2	EMAC	Ethernet RMII TXD0
PTC3	GPIO	Ethernet PHY reset
PTC17	EMAC	Ethernet RMII RX_DV
PTD7	EMAC	Ethernet RMII TXD1
PTD11	EMAC	Ethernet RMII REF_CLK
PTD12	EMAC	Ethernet RMII TX_EN

Ethernet

The board carries a Microchip LAN8741 10/100 Mbit/s PHY on MDIO address 0, connected to the MCXE31B EMAC over RMII. The EMAC is a Synopsys DesignWare Ethernet QoS core and is driven by the generic drivers/ethernet/dwc_mac driver, not by the NXP HAL based eth_nxp_enet_qos driver.

The PHY sources the 50 MHz RMII reference clock, which the SoC takes in on PTD11 and divides by two to clock the MAC’s MII side. The driver also supports MII, selected with phy-connection-type, though this board is wired for RMII.

System Clock

The MCXE31B SoC is configured to use PLL running at 160MHz as a source for the system clock.

Serial Port

The MCXE31B LPUART5 is used for the console.

Programming and Debugging

The frdm_mcxe31b board supports the runners and associated west commands listed below.

	flash	debug	attach	debugserver	rtt	reset
jlink	✅	✅	✅	✅	✅	✅
linkserver	✅ (default)	✅ (default)	✅	✅

Build and flash applications as usual (see Building an Application and Run an Application for more details).

Configuring a Debug Probe

A debug probe is used for both flashing and debugging the board. This board is configured by default to use the MCU-Link CMSIS-DAP Onboard Debug Probe.

Using LinkServer

Linkserver is the default runner for this board, and supports the factory default MCU-Link firmware. Follow the instructions in MCU-Link CMSIS-DAP Onboard Debug Probe to reprogram the default MCU-Link firmware. This only needs to be done if the default onboard debug circuit firmware was changed. To put the board in ISP mode to program the firmware, short jumper JP3.

Using J-Link

There are two options. The onboard debug circuit can be updated with Segger J-Link firmware by following the instructions in MCU-Link JLink Onboard Debug Probe. To be able to program the firmware, you need to put the board in ISP mode by shorting the jumper JP3. The second option is to attach a J-Link External Debug Probe to the 10-pin SWD connector (J14) of the board. For both options use the -r jlink option with west to use the jlink runner.

west flash -r jlink

Configuring a Console

Connect a USB cable from your PC to J13, and use the serial terminal of your choice (minicom, putty, etc.) with the following settings:

Speed: 115200
Data: 8 bits
Parity: None
Stop bits: 1

Flashing

Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b frdm_mcxe31b samples/hello_world
west flash

Open a serial terminal, reset the board (press the RESET button), and you should see the following message in the terminal:

*** Booting Zephyr OS build v4.2.0-2092-g17e93a718422 ***
Hello World! frdm_mcxe31b/mcxe31b

Debugging

Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b frdm_mcxe31b samples/hello_world
west debug

Open a serial terminal, step through the application in your debugger, and you should see the following message in the terminal:

*** Booting Zephyr OS build v4.2.0-2092-g17e93a718422 ***
Hello World! frdm_mcxe31b/mcxe31b

Troubleshooting

Using Segger SystemView and RTT

Note that when using SEGGER SystemView or RTT with this SOC, the RTT control block address must be set manually within SystemView or the RTT Viewer. The address provided to the tool should be the location of the _SEGGER_RTT symbol, which can be found using a debugger or by examining the zephyr.map file output by the linker.

The RTT control block address must be provided manually because this SOC supports ECC RAM. If the SEGGER tooling searches the ECC RAM space for the control block a fault will occur, provided that ECC is enabled and the RAM segment being searched has not been initialized to a known value.

QSPI Flash

The FRDM-MCXE31B board is populated with an on-board Winbond W25Q64 (64 Mbit) QSPI NOR flash. The QSPI data and clock signals are not connected to the flash by default, so the w25q64 node is disabled on the default board target and enabled by the w25q64 board revision.

Note

In order to use the on-board QSPI flash, populate resistors R126, R128, R129, R130, R131 and R133, and remove resistors R153 and R154.

Once the rework is done, build for the frdm_mcxe31b@w25q64 revision to exercise the flash with the MSPI flash sample (samples/drivers/mspi/mspi_flash):

# From the root of the zephyr repository
west build -b frdm_mcxe31b@w25q64 samples/drivers/mspi/mspi_flash
west flash

Support Resources for Zephyr

NXP Board Support Status
NXP Zephyr Downstream Software Development Kit
MCUXpresso for VS Code documentation, and Zephyr lab guides
NXP Zephyr Knowledge Hub
NXP’s Zephyr landing page (including training resources)
NXP Support Community forum for Zephyr