FRDM-IMX91S Hardware Introduction The FRDM i.MX 91S Development Board is a cost-effective, compact platform built around the i.MX 91 applications processor, optimized for embedded Linux development. It integrates the NXP IW610 wireless module, enabling robust Wi-Fi 6 + Bluetooth LE 5.4 / 802.15.4 connectivity for Industrial and IoT applications. Designed for rapid prototyping, the board supports GoPoint for i.MX Applications Processors, providing a suite of pre-integrated demos and reference implementations. The FRDM i.MX 91S features integrated 256MB NAND flash memory supporting direct boot (NAND boot). This includes a deeply trimmed, lightweight file system optimized for reliability and minimal resource consumption. Its small footprint maximizes usable storage while ensuring efficient operation. This file system serves as an ideal starting point – its modular design is fully customizable, allowing you to tailor it further to your specific application needs and optimize performance. Get to know FRDM-IMX91S Development Boaard Specifications i.MX 91 applications processor with 1x Arm® Cortex®-A55 LPDDR4 16-bit 512MB QSPI NAND Flash, 256MB Power Management IC (PMIC) MicroSD 3.0 card slot One USB 2.0 Type-C connector One USB 2.0 Type-C for debug One USB 2.0 Type-A connector One USB Type-C PD only Onboard Wi-Fi® 6 + Bluetooth® LE 5.4/802.15.4 module One 2x5 Pin NXP custom interface with: One CAN port Two channels for ADC I2C/I3C expansion One 1 Gbps Ethernet (ETER) External RTC with coin cell connector 40 pin (2 x 20) expansion I/O Feature FRDM-IMX91S SoC Package 11 x 11 NVM NAND flash 256 MB DRAM NANYA 512 MB PMIC PF9453 WiFi Module u-blox MAYA-W476 on-board USB TYPE C Type-C+Type-A ENET 1xGbe Display (Parallel RGB LCD) 2x20 EXPI Camera (Parallel Camera) 2x20 EXPI 2x20 Expansion Interface Y CAN BUS Y MicroSD Y UART Y Audio MQS Power Connector Type-C PCB layers 6 Base Board DIM 6.5 x 9.5 cm   NXP Devices On-board PMIC PF9453 Real time clock/calendar PCF2131 WIFI/BLE/802.15.4 Tri-Radio IW610 in u-blox module CAN Transceiver TJA1051T/3 IIC Extends GPIO PCAL6524   Expansion Boards ​8MIC-RPI-MX8: 8-microphone array proto board for voice enablement MX93AUD-HAT: Audio expansion board with multiple features Useful Links −i.MX Yocto Project User’s Guide​ −i.MX Linux User’s Guide ​−i.MX Linux Reference Manual​ −i.MX Porting Guide -i.MX Debian Linux SDK User Guide

This article will give a brief introduction of FRDM-IMX91S software release. FRDM-IMX Yocto BSP Release i.MX FRDM Development software release contains prebuilt images, documentation, and i.MX FRDM Yocto layer for FRDM-IMX boards. It also includes support for Matter.  Based on i.MX SW 2024 Q3 BSP release Linux kernel: 6.6.36_2.1.0 u-boot: 2024.04 i.MX FRDM Yocto layer source: https://github.com/nxp-imx-support/meta-imx-frdm For more details, please check i.MX FRDM Software User Guide. FRDM-IMX91S accessories and corresponding dtb: 5-inch Tianma LCD: imx91-11x11-frdm-imx91s-tianma-wvgapanel. dtb RPI-CAM-INTB: imx91-11x11-frdm-imx91s-mt9m114.dtb MX93AUD-HAT: imx91-11x11-frdm-imx91s-aud-hat.dtb 8MIC-RPI-MX8: imx91-11x11-frdm-imx91s-8mic.dtb Build FRDM-IMX91S SD boot image: Download i.MX SW 2024 Q3 Release: $ repo init -u https://github.com/nxp-imx/imx-manifest -b imx-linux-scarthgap -m imx-6.6.36-2.1.0.xml $ repo sync Integrate meta-imx-frdm layer into Yocto code base: $ cd ${MY_YOCTO}/sources $ git clone https://github.com/nxp-imx-support/meta-imx-frdm.git Yocto Project Setup: $ cd ${MY_YOCTO} $ MACHINE=imx91frdmimx91s DISTRO=fsl-imx-xwayland source sources/meta-imx-frdm/tools/imx-frdm-setup.sh -b frdm-imx91s Build images: $ bitbake imx-image-full Flash SD card image using dd: $ zstdcat imx-image-full-imx91frdmimx91s.rootfs.wic.zst | sudo dd of=/dev/sdx bs=1M && sync Or use uuu to burn image to SD card: $ uuu -b sd_all imx-image-full-imx91frdmimx91s.rootfs.wic.zst Build FRDM-IMX91S NAND boot image: Download i.MX SW 2024 Q3 Release: $ repo init -u https://github.com/nxp-imx/imx-manifest -b imx-linux-scarthgap -m imx-6.6.36-2.1.0.xml $ repo sync Integrate meta-imx-frdm layer into Yocto code base: $ cd ${MY_YOCTO}/sources $ git clone https://github.com/nxp-imx-support/meta-imx-frdm.git Yocto Project Setup: $ cd ${MY_YOCTO} $ MACHINE=imx91frdmimx91s DISTRO=fsl-imx-xwayland source sources/meta-imx-frdm/tools/imx-frdm-setup.sh -b frdm-imx91s Configure U-Boot to nand boot: $ echo "UBOOT_CONFIG = \"nand\"" >> conf/local.conf Build base rootfs: $ bitbake imx-image-base Build initramfs: $ bitbake fsl-image-mfgtool-initramfs Use uuu script to flash nand boot image:  $ sudo uuu example_kernel_nand.uuu FRDM-IMX91S Matter support  Based on i.MX Matter 2024 Q3. To include Matter support, please follow below steps to include Matter layer into Yocto build. Download i.MX SW 2024 Q3 BSP Release: $ repo init -u https://github.com/nxp-imx/imx-manifest -b imx-linux-scarthgap -m imx-6.6.36-2.1.0.xml $ repo sync Download i.MX Matter Yocto layer: $ cd ${MY_YOCTO}/sources/meta-nxp-connectivity $ git remote update $ git checkout imx_matter_2024_q3 Integrate meta-imx-frdm layer into Yocto code base: $ cd ${MY_YOCTO}/sources $ git clone https://github.com/nxp-imx-support/meta-imx-frdm.git Yocto Project Setup: $ cd ${MY_YOCTO} $ MACHINE=imx91frdmimx91s-iwxxx-matter DISTRO=fsl-imx-xwayland source sources/meta-imx-frdm/tools/imx-frdm-matter-setup.sh bld-xwayland-frdmimx91s Build images:  $ bitbake imx-image-multimedia Related Documentation i.MX FRDM Software User Guide More information about i.MX productions can be found at(http://www.nxp.com/imxlinux) i.MX Yocto Project User’s Guide​ i.MX Linux User’s Guide​ i.MX Linux Reference Manual​ i.MX Porting Guide

Ready to scale your edge designs? Discover how NXP’s MCX N947 and MCX N236 microcontrollers—and their FRDM evaluation boards—bring performance, power efficiency, and ML capabilities to your next IoT or industrial project. From dual-core processing to ultra-low-power sensing, this article breaks down what makes these MCUs ideal for intelligent edge development.