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NXP MIMXRT685-EVK

Overview

The i.MX RT600 is a crossover MCU family optimized for 32-bit immersive audio playback and voice user interface applications combining a high-performance Cadence Tensilica HiFi 4 audio DSP core with a next-generation Cortex-M33 core. The i.MX RT600 family of crossover MCUs is designed to unlock the potential of voice-assisted end nodes with a secure, power-optimized embedded processor.

The i.MX RT600 family provides up to 4.5MB of on-chip SRAM and several high-bandwidth interfaces to access off-chip flash, including an Octal/Quad SPI interface with an on-the-fly decryption engine.

MIMXRT685-EVK

Hardware

  • MIMXRT685SFVKB Cortex-M33 (300 MHz, 128 KB TCM) core processor with Cadence Xtensa HiFi4 DSP

  • Onboard, high-speed USB, Link2 debug probe with CMSIS-DAP protocol (supporting Cortex M33 debug only)

  • High speed USB port with micro A/B connector for the host or device functionality

  • UART, I2C and SPI port bridging from i.MX RT685 target to USB via the on-board debug probe

  • 512 MB Macronix Octal SPI Flash operating at 1.8 V

  • 4.5 MB Apmemory PSRAM

  • Full size SD card slot (SDIO)

  • NXP PCA9420UK PMIC

  • User LEDs

  • Reset and User buttons

  • Arduino and PMod/Host expansion connectors

  • NXP FXOS8700CQ accelerometer

  • Stereo audio codec with line in/out and electret microphone

  • Stereo NXP TFA9894 digital amplifiers, with option for external +5V power for higher performance speakers

  • Support for up to eight off-board digital microphones via 12-pin header

  • Two on-board DMICS

For more information about the MIMXRT685 SoC and MIMXRT685-EVK board, see these references:

Supported Features

The mimxrt685_evk board configuration supports the following hardware features:

Interface

Controller

Driver/Component

NVIC

on-chip

nested vector interrupt controller

SYSTICK

on-chip

systick

IOCON

on-chip

pinmux

GPIO

on-chip

gpio

USART

on-chip

serial port-polling

I2C

on-chip

i2c

The default configuration can be found in the defconfig file:

boards/arm/mimxrt685_evk/mimxrt685_evk_cm33_defconfig

Other hardware features are not currently supported by the port.

Connections and IOs

The MIMXRT685 SoC has IOCON registers, which can be used to configure the functionality of a pin.

Name

Function

Usage

PIO0_2

USART

USART RX

PIO0_1

USART

USART TX

PIO0_14

GPIO

GREEN LED

PIO1_1

GPIO

SW0

PIO0_17

I2C

I2C SDA

PIO0_18

I2C

I2C SCL

PIO1_5

GPIO

FXOS8700 TRIGGER

System Clock

The MIMXRT685 SoC is configured to use the internal FRO at 48MHz as a source for the system clock. Other sources for the system clock are provided in the SOC, depending on your system requirements.

Serial Port

The MIMXRT685 SoC has 8 FLEXCOMM interfaces for serial communication. One is configured as USART for the console and the remaining are not used.

Programming and Debugging

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 LPC-Link2.

Configuring a Console

Connect a USB cable from your PC to J16, 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. This example uses the J-Link Debug Host Tools as default.

# From the root of the zephyr repository
west build -b mimxrt685_evk_cm33 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 v1.14.0 *****
Hello World! mimxrt685_evk_cm33

Debugging

Here is an example for the Hello World application. This example uses the J-Link Debug Host Tools as default.

# From the root of the zephyr repository
west build -b mimxrt685_evk_cm33 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 zephyr-v2.3.0 *****
Hello World! mimxrt685_evk_cm33