i.MX Processors Knowledge Base

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This patch series enables the external 3.3 V and 5 V power rails used by the Raspberry Pi expansion connector on the i.MX93-QSB, i.MX93-FRDM, and i.MX91-FRDM boards. These regulators were already defined in the device tree but left disabled by default. By activating them, the RPI-compatible expansion header can properly power external modules, HATs, and add‑on boards. Changes by board: i.MX93-QSB Enables the 3.3 V and 5 V external supply lines used by the RPI connector. i.MX93-FRDM Enables the 3.3 V and 5 V external supply lines used by the RPI connector. i.MX91-FRDM Enables the 3.3 V and 5 V external supply lines used by the RPI connector. Purpose: Provide proper power to the Raspberry Pi compatible expansion port. Improve hardware compatibility for users attaching external HATs or modules. Align all i.MX9 reference boards to use a consistent power‑tree configuration for the RPI connector.

We are pleased to announce that Config Tools for i.MX v25.12 are now available. Downloads & links To download the installer for all platforms, please login to our download site via: https://www.nxp.com/design/designs/config-tools-for-i-mx-applications-processors:CONFIG-TOOLS-IMX Please refer to Documentation for installation and quick start guides. For further information about DDR config and validation, please go to this blog post. Release Notes Full details on the release (features, known issues...) DDR tool – Support for detecting multiple boards connected to the host system is added. – Automatic detection and selection of newly connected COM ports is implemented. – A Connection Test option to validate connectivity before running tests on the target is introduced. – i.MX 93 EVK LP4 configuration is added. – Training execution time information for i.MX 95 and i.MX 943 is included in logs. – Bus signal naming in the UI to align with i.MX pin naming conventions is consolidated. – CA bus values for i.MX943 with LPDDR4 are updated. – DRAM density calculation for i.MX 95 and i.MX 943 with LP4/4x is corrected. – Incorrect calculation of number of banks for i.MX 8M with DDR3L is fixed. – CS1_BNDs calculation for i.MX 91 is corrected. SerDes tool – i.MX 943 RFP support is added. System Manager – The ability to export user configuration in the CFG format is added. – Information about atomic resources to the Details view is added. – Generation and configuration of the config_fusa.h file is supported. – Resource and template assignment is improved. – Grayed-out resource assignments for unavailable configuration parameters in the Resources view are implemented. – Validation of configuration and user input is improved. – Problem decorators to the System and Boot view are added. – Design of the Boot and Details view is improved. – 5600 MT/s for i.MX 95 and i.MX 943 with LPDDR5 is enabled. – LP4/4x settings for DDR_SDRAM_ZQ_CNTL for i.MX 95 and i.MX 943 are updated. – Dual-rank configurations for i.MX 91 and i.MX 93 are updated. – LP4/4x configuration to support non-binary densities for i.MX 95 and i.MX 943 is updated. – Support for non-binary aligned LP4 density for i.MX 91 is added. – FRDM board support (LPDDR4X 15x15 at 4000 MT/s) for i.MX 95 is added. – Timing file discrepancies for i.MX 8MN with DDR3L are fixed. – Issue where changing PHY log level did not update generated code is fixed.

This article describes how to create a tiny rootfs based on BusyBox. Test platform: i.MX 95 19x19 LPDDR5 EVK. The attached layer can be used with other platforms as well. Software: Linux BSP 6.12.34-2.1.0 Boot device: SD card This article provides a custom meta-tiny-rootfs layer, to simplify the enablement. The layer: creates a custom distribution based on Poky, with no extra features creates a custom image based on BusyBox that only starts a terminal removes most of the machine features uses musl, instead of glibc Using the default DISTRO=fsl-imx-wayland and core-image-minimal, the rootfs size is 800MB. Using the custom DISTRO=tiny-rootfs and core-image-tiny, the rootfs size reduces to 2.6MB. How to? 1. Prepare the Yocto environment according to Section 3, 4, 5 in i.MX Yocto Project User's Guide. In the next commands, we'll assume the Yocto directory is imx-yocto-bsp, and the build directory is build. 2. Configure the build directory: cd ~/imx-yocto-bsp/ DISTRO=fsl-imx-wayland MACHINE=imx95-19x19-lpddr5-evk source ./imx-setup-release.sh -b build Note: The imx-setup-release.sh script accepts only Wayland distributions. We'll set the custom distro at the next step. 3. Set the custom distro. In the build directory, run: echo 'DISTRO = "tiny-rootfs"' >> conf/local.conf 4. Download the meta-tiny-rootfs archive, and extract it into the ~/imx-yocto-bsp/sources directory. cd ~/imx-yocto-bsp/sources tar -xvf meta-tiny-rootfs.tar.gz 5. Add the meta-tiny-rootfs layer to BBLAYERS: cd ~/imx-yocto-bsp/build bitbake-layers add-layer ../sources/meta-tiny-rootfs 6. Build the core-image-tiny image. bitbake core-image-tiny 7. Write the image on an SD card, and boot. You should be able to see a similar log: [ 6.183401] Run /sbin/init as init process init started: BusyBox v1.37.0 () starting pid 163, tty '': '/bin/mount -t proc proc /proc' starting pid 164, tty '': '/bin/mount -t sysfs sysfs /sys' starting pid 165, tty '': '/bin/mount -t devtmpfs devtmpfs /dev' mount: mounting devtmpfs on /dev failed: Resource busy starting pid 166, tty '': '/bin/mount -o remount,rw /' [ 6.246037] EXT4-fs (mmcblk1p2): re-mounted a5abac39-6c11-419f-97ef-86532e2616ad. starting pid 167, tty '': '/bin/mkdir -p /dev/pts' starting pid 168, tty '': '/bin/mount -t devpts devpts /dev/pts' starting pid 169, tty '': '/bin/mount -a' starting pid 170, tty '': '/sbin/swapon -a' starting pid 176, tty '': '/etc/init.d/rcS' starting pid 177, tty '/dev/ttyLP0': '/usr/sbin/ttyrun ttyLP0 /sbin/getty 115200 ttyLP0' Tiny Rootfs Operating System 1.0.0 imx95-19x19-lpddr5-evk /dev/ttyLP0 imx95-19x19-lpddr5-evk login: How to add additional features? If you want to add additional features to DISTRO_FEATURES, MACHINE_FEATURES, or IMAGE_FEATURES, please use the DISTRO_TINY_FEATURES, MACHINE_TINY_FEATURES and IMAGE_TINY_FEATURES variables. For example, to add bluetooth to MACHINE_FEATURES, add the following line in conf/local.conf. MACHINE_TINY_FEATURES = "bluetooth" Note: If you need to add a package that requires the full libc (instead of musl), add the following in conf/local.conf: TCLIBC = "glibc" These optimizations were inspired by this presentation: Honey, I shrunk the rootfs!

Question: What does it means by depending on load? Is there a value? This is related with i.MX6D Answer: The comment about the "load" means the total system load on the 2.5V rail. We understand that people design systems, not just MX6 devices. The documentation confusion stems from the design team changing from allowing customers to use the LDOs to power system devices back to just using the LDOs to power the MX6. Reasons - thermals, and also concern for uncontrolled system noise injection into the MX6 and causing failures.

The purpose of this page is to provide supportive information for the selection of suitable camera modules that are supported by the i.MX95. The guide is attached in this page. This helps customers evaluate project feasibility and integration aspects when considering i.MX95 SoCs for their products. It is strongly recommended to consult with NXP and the camera module vendor before finalizing the choice of the camera part number to ensure compatibility, availability, longevity, and pricing requirements. NXP Supported Sensors: Sensor Vendor Image Sensor Max Resolution Camera Module OmniVision OS08A20 8MP IMX95-OS08A20 | NXP Semiconductors EXPI-OS08A20 OmniVision OX05B1S 5MP OmniVision OX03C10 3MP Onsemi AR0144 1MP AR0144 Partner Enabled Sensors: Partner Sensor Vendor Image Sensor Max Resolution ISP Tuning Camera Module Location FRAMOS Sony IMX662 2MP ✔ FSM:GO Munich, Germany/ Canada/USA Sony IMX678 8MP Sony IMX900 3.2MP Sony IMX676 12MP Onsemi Onsemi AR2020 19MP Module available through Future Electronics Entron OmniVision OS08A20 8MP ✔ EXPI-OS08A20 China Onsemi AR0820 8MP Order with Entron Onsemi AR0823 8MP Technexion Onsemi AR0144 1MP Onsemi AR0145 1MP Onsemi AR0234 2MP Onsemi AR0235 2MP Onsemi AR0236 2MP Onsemi AR0521 5MP Onsemi AR0522 5MP Onsemi AR0544 5MP Onsemi AR0821 8MP Onsemi AR0822 8MP Onsemi AR0830 8MP Onsemi AR1335 13MP PHYTEC Onsemi AR0144 1MP Germany/ China/India/ USA Onsemi AR0234 2.3MP Onsemi AR0521 5MP E-consystems Sony IMX662 2.4MP Riverside, CA, USA/India Sony IMX900 3.2MP

Poring from MCIMX6Y2CVM05AB to MCIMX6Y1DVM05AB Backgroud: Our customers encounter Kernel stuck at starting kernel issue. Here is detail description as below: (1 )Using customer board, and the main chip is MCIMX6Y1DVM05AB. (2) MCIMX6Y2CVM05AB works fine using the same image. (3)The kernel version is L5.10.52. But the old L4.14.98 works fine. (4)Using imx6ull evk's dtb has the same symptom. (imx6ull-14x14-evk.dtb in L5.10.52 prebuild image from NXP. (5)The L4.14.98 versionBSP both MCIMX6Y1DVM05AB and MCIMX6Y2CVM05AB can work well For the L5.10.52 only the MCIMX6Y2CVM05AB can work. Kernel crash at here: Generally speaking, most customer need to porting from old chip to new, for this customer need to use porting from the new product to old products they have their reasons. Two reasons: (1) Their previous project use MCIMX6Y1DVM05AB. And also have MCIMX6Y1DVM05AB stock. (2) And the customer needs 15kpcs for urgent demand. But there is no MCIMX6Y2CVM05AB stock in their city. Porting steps: For these two products, they are difference, but most pins to pins in design. 1\Found the difference for this two product: See the datasheet: https://www.nxp.com.cn/docs/en/data-sheet/IMX6ULLCEC.pdf https://www.nxp.com.cn/docs/en/data-sheet/IMX6ULLIEC.pdf For the MCIMX6Y1DVM05AB do not have the LCD/CSI, one CAN, one Ethernet,one ADC. 2\Check the customer’s board dts setting and modify Ask customer for their Board dts file and check: The MCIMX6Y1DVM05AB chip has only followed features, so customer should make sure the related drivers are removed from dts. That means in climaxL5.10.52.7z, customer should disable the followed drivers: pxp, lcdif, can2. (csi and fec2 are already disabled) (1) Disable the fec2 (2)CSI disable (3)Lcdif disable (4)CAN 2 Remove Result: After remove these unused functions. The MCIMX6Y1DVM05AB could boot well on customer’s board. If customer use the MCIMX6Y2CVM05AB, all these functions need to add.

SW : uboot-imx lf_v2025.04 HW : i.MX 8MP EVK board, Oscilloscope 1. Introduction This guide explains the concept of DDR clock spread spectrum on the i.MX 8MP EVK platform. Note that the official NXP BSP does not enable this feature by default. Additionally, this guide provides an example code patch and verification steps to enable the LPDDR4 clock spread spectrum feature on the NXP i.MX 8MP EVK board. 2. What is Spread Spectrum? Spread Spectrum (SS) is a technique used to reduce electromagnetic interference (EMI) by slightly modulating the clock frequency around its nominal value. Instead of operating at a fixed frequency (e.g., 800 MHz), the clock signal is varied within a small range (e.g., ±0.5%). This modulation spreads the energy of the clock signal over a wider frequency band, reducing the peak energy at any single frequency. In other words, SS does not change the average clock speed significantly, but it helps to distribute the spectral energy, making the system less likely to violate EMI regulations. 3. Why Enable Spread Spectrum on DRAM Clock? Enabling Spread Spectrum on the DRAM clock helps reduce electromagnetic interference (EMI) by slightly modulating the clock frequency, lowering peak emissions and making it easier to meet regulatory standards such as FCC and CE. This approach improves system reliability by minimizing interference with other components, offers a cost-effective alternative to hardware changes like shielding or PCB redesign, and is widely adopted in high-speed interfaces such as DDR, PCIe, and SATA to ensure compliance without additional hardware complexity. 4. Related registers CCM_ANALOG_DRAM_PLL_SSCG_CTRL Note : PLL_MFREQ_CTL[19 : 12] : Value of modulation frequency control The larger the mfr value, the lower the MF value (the slower the modulation); the smaller the mfr value, the higher the MF value. MF : The frequency of spread spectrum modulation is the speed at which the triangular/sawtooth modulated wave travels back and forth once per second, measured in Hz (commonly in the tens of kHz range). The speed of the spread spectrum "jitter" is determined. Usually, around 20–50 kHz is chosen to make the energy "swipe evenly" within the bandwidth of the EMI test receiver, thereby reducing the peak radiation at a certain frequency point. PLL_MRAT_CTL[9 : 4] : Value of modulation rate control The larger mrr is, the larger MR is (the wider the range); similarly, MR is also directly proportional to mfr and inversely proportional to m. MR : Peak-to-peak percentage of spread spectrum (the percentage of the total range of the clock frequency swinging around the center value). For example, MR = 0.5% means that the frequency swings around the center value by a total of 0.5% (if it is center-spread spectrum, it is usually ±0.25%).The MR determines the depth (width) of the spread spectrum. The larger the MR, the wider the spectral energy distribution and the lower the peak value, but it comes at the cost of jitter/timing margin (timing should be carefully selected for DDR, SerDes, etc.). 5. About Uboot code patch. Please refer the attachment patch file. At high DRAM frequency, Enable SS may cause not stable problem. So, in this case, I will choose 2400Mbps data clock run the test. Firstly, we should make sure that our code include the 2400Mbps PLL setting. DRAM data speed is 2400Mbps, the DRAM clock is 1200MHz. So the DDRC PLL clock should set up with 600MHz. For example, refer the below code. static struct imx_int_pll_rate_table imx8mm_fracpll_tbl[] = { PLL_1443X_RATE(1000000000U, 250, 3, 1, 0), PLL_1443X_RATE(933000000U, 311, 4, 1, 0), PLL_1443X_RATE(900000000U, 300, 2, 2, 0), PLL_1443X_RATE(800000000U, 200, 3, 1, 0), PLL_1443X_RATE(750000000U, 250, 2, 2, 0), PLL_1443X_RATE(650000000U, 325, 3, 2, 0), PLL_1443X_RATE(600000000U, 300, 3, 2, 0), // 2400Mbps PLL_1443X_RATE(594000000U, 99, 1, 2, 0), PLL_1443X_RATE(400000000U, 400, 3, 3, 0), PLL_1443X_RATE(266000000U, 266, 3, 3, 0), PLL_1443X_RATE(167000000U, 334, 3, 4, 0), PLL_1443X_RATE(100000000U, 200, 3, 4, 0), }; PLL output calculator formula is : PLL_out = 24MHz*mdiv/pdiv/(2^sdiv) So, 2400MHz * 300 / 3 / 2^2 = 600MHz 6. Test result Non Enable SS Enable SS with 1% MR and Down spread Enable SS with 2% MR and Down spread Enable SS with 2% MR and Center spread

In some applications, we need to shift frequencies to avoid interference from certain frequencies, such as shifting to avoid Wi-Fi interference. The document is a guide for shifting DDR3 frequency. The document uses the iMX8M Nano DDR3 as an example, but the process is the same for the iMX8M mini, iMX8M Plus, LPDDR4, etc. The main issue is resolving the DDR pll configuration. Before reading this article, we assume you are already familiar with using the DDR stress tool and DDR config rpa, or the DDR tool of the config tools. pll_to_table_entry_rates.py can help you to find the settings.

i.MX Processors Knowledge Base

i.MX Processors Knowledge Base

Discussions

Enable 3.3 V and 5 V Regulators for Expansion Header on i.MX9 boards

Config Tools for i.MX v25.12 Now Available

Using Yocto to build a minimal (3MB) Linux File System for i.MX MPUs

Q&A: What is the value on NVCC_LVDS_2P5?

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i.MX95 ISP Camera Compatibility Guide

mx6ul-evb-revb-obds.bin

Poring from MCIMX6Y2CVM05AB to MCIMX6Y1DVM05AB

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enable dcp in 3.14 kernel for mx6sl

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single_channel.patch

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i.MX51 PDK operating system with LTIB

The patch to fix the stall problem when imx28 host connected with cdc_ether device

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Fuse Read and Write tool in Linux Userspace for i.MX 9 series

Enable and verify i.MX 8MP LPDDR4 Clock Spread Spectrum

iMX8MN DDR3 Frequency Shifting

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