Accelerate MCU and MPU Projects Using a Flexible Development Platform

Embedded systems and their applications are rapidly diversifying, and so are the processors that serve them. In response, embedded processors are becoming increasingly sophisticated, providing engineers with an ever-growing list of options that often overlap in features. While more choices are always welcome, exploring the possibilities can be prohibitively time-consuming. To succeed in a dynamic environment, developers need a means of rapidly evaluating multiple silicon options, from microcontroller units (MCUs) to microprocessor units (MPUs), while streamlining the prototyping process.

One way to help designers is to take a building-block approach to hardware. By combining simplified development boards with an extensive library of expansion modules and supporting software, designers can mix and match as needed.

This article reviews how embedded system design requirements are changing and what those changes mean for processor selection. It then shows how a platform from NXP enables designers to explore multiple processor classes, scaling from low-power MCUs to highly integrated Linux-class MPUs and application processors.

The blurring boundaries of embedded design

Until recently, most embedded applications fit into categories with well-defined boundaries. Simple I/O and control logic were the domain of 8-bit MCUs; 32-bit MCUs handled complex real-time tasks. Applications requiring a full operating system (OS) or a graphical user interface (GUI) were firmly in MPU territory.

Today, those boundaries are blurred. Many traditional 8-bit applications have been pushed into the 32-bit domain as previously standalone applications add sophisticated connectivity. Complex software stacks are proliferating across real-time applications, merging the demands of MCU and MPU applications. At the same time, artificial intelligence (AI) and machine learning (ML) are being integrated into an increasingly wide range of applications.

The distinctions between processor classes have also gotten fuzzy. High-performance MCUs now feature graphics accelerators and AI/ML capabilities that were once reserved for high-end MPUs. MPUs are adding real-time capabilities that were previously only available on MCUs. Adding complexity, the demand for high-end graphics, AI, and other sophisticated features has driven the introduction of application processors, with architectures borrowed from mobile phones.

All this is happening as innovation continues to accelerate. Between the start of a design cycle and the product launch, market dynamics can significantly shift project requirements. For example, a headless MCU-based design might unexpectedly sprout a touchscreen, necessitating a leap to an MPU. Conversely, a product marketing team might decide at the last minute that a high-end product needs to be accompanied by an entry-level version, creating a rush to find a lower-cost processor.

These trends and shifts have created a need for a processor evaluation ecosystem that enables designers to explore various options easily. Traditional evaluation boards have struggled to meet this demand. Often intended to demonstrate every significant feature of a processor family, they tended to use complex designs optimized for a narrow range of applications. As a result, the effort invested in one board was rarely transferable to another.

Flexible platform enables faster processor evaluation

To address the needs of embedded system designers, NXP took a fresh look at the problem and developed the FRDM development platform (Figure 1). Instead of packing in every possible feature, FRDM boards include only the essentials: the processor, memory, and basic I/O. Application-specific functionality can then be added by tapping into the vast ecosystem of Arduino (Arduino), Pmod (Digilent), and mikroBUS (MikroElektronika) expansion headers. NXP supports this modular approach with its Expansion Board Hub, which offers options for displays, sensors, communication interfaces, and more.

Figure 1: FRDM boards include only the essentials, leaving functionality like displays and I/O to standards-based expansion boards. (Image source: NXP)

This building-block approach makes it easier to extend functionality and reuse hardware across projects. Because the expansion modules share the same industry-standard interfaces, the same peripheral board can be evaluated with different processors. A designer might, for example, validate a sensor module on an entry-level MCU platform, then reuse that exact hardware with a high-performance MPU, all without redesigning the prototype.

What makes this flexibility so powerful is the breadth of Arm-based processors supported by the FRDM platform. The lineup begins with ultra-low-power, entry-level MCUs and extends through a wide range of feature-rich devices, including options tailored for motor control, graphics, and wireless connectivity. At the high end, it encompasses MPUs and application processors with gigahertz (GHz)-class performance and advanced features, such as AI accelerators.

Getting started with an entry-level MCU development board

The FRDM-MCXC444 (Figure 2) illustrates the advantages of the FRDM platform. This entry-level board provides an ultra-low-power foundation for cost-sensitive embedded applications, featuring the MCXC444VLH MCU. This MCU is part of NXP’s MCX C series, which is designed for applications where power efficiency and low cost are paramount.

Figure 2: The FRDM-MCXC444 entry-level board features a low-power MCXC444VLH MCX C series MCU, a small LCD, and USB ports. (Image source: NXP)

The MCXC444VLH is built around an Arm Cortex-M0+ core running up to 48 megahertz (MHz). It draws 54 microamperes per MHz (µA/MHz) in very-low-power run mode and just 1.96 µA in deep sleep mode. This low current draw makes it exceptionally well-suited for battery-powered applications.

Another distinguishing feature of the MCXC444VLH is its integrated segment LCD controller, which supports up to 24 × 8 or 28 × 4 segments without requiring external drivers. It also includes full-speed USB 2.0 functionality, without the need for an external crystal, thereby reducing bill of material (BOM) costs and board complexity.

The FRDM-MCXC444 board showcases these features with a built-in LCD and USB. Other notable features include an accelerometer and a light sensor, enabling prototyping of sensor-driven designs. The board is a good starting point for battery-operated devices requiring simple user interfaces and periodic connectivity.

Jump-start motor control with a mainstream MCU development board

Moving up to the mid-range, the FRDM-MCXA346 (Figure 3) highlights how the FRDM platform supports more refined control tasks. This board targets motor control and features the MCXA346VLQ MCU, part of NXP’s MCX A series, which is designed for mainstream applications requiring sophisticated integration.

Figure 3: The FRDM-MCXA346 evaluation board is based on an MCXA346VLA MCX A series MCU and offers a rich set of features for industrial control, including CAN FD. (Image source: NXP)

The MCXA346VLQ is built around an Arm Cortex-M33 core running at 180 MHz. It includes 1 megabyte (Mbyte) of flash memory and 256 kilobytes (Kbytes) of static random access memory (SRAM), providing ample storage for application code and data. The processor’s floating point unit (FPU) and digital signal processing (DSP) extensions make it well-suited for complex control algorithms.

For motor control applications, the MCXA346VLQ provides comprehensive hardware support. Two FlexPWM modules, each with four submodules, provide up to 16 complementary pulse width modulation (PWM) outputs for driving brushless DC (BLDC) and permanent magnet synchronous motors (PMSMs). Four 16-bit analog-to-digital converters (ADCs) sample up to 3.2 megasamples per second (Msamples/s), enabling precise monitoring across multiple motor phases. Two quadrature encoder/decoder (eQDC) modules handle rotor position feedback, while two and/or/invert (AOI) modules provide hardware logic for complex control sequences.

The FRDM-MCXA346 board offers direct access to key I/O, including full-speed USB and CAN FD for industrial networking applications. The board supports parallel display and camera interfaces, allowing for GUI development without the need for external hardware. These features make the board well-suited to developing industrial equipment that requires a human-machine interface (HMI).

Tackle edge AI with a high-performance MPU development board

At the top of the FRDM range, the FRDM-IMX8MPLUS (Figure 4) demonstrates how the platform extends beyond MCUs to encompass complete application processor design. This board is based on the MIMX8ML8DVNLZAB, a member of NXP’s i.MX 8M Plus family that features multi-core GHz-plus processors and AI accelerators.

Figure 4: The FRDM-IMX8MPLUS development board is based on the MIMX8ML8DVNLZAB MPU from the i.MX 8M Plus family; it includes extensive multimedia interfaces and AI acceleration. (Image source: NXP)

Specifically, the FRDM-IMX8MPLUS combines four Arm Cortex-A53 cores running up to 1.8 GHz with a dedicated Cortex-M7 real-time core running at 800 megahertz (MHz), and a neural processing unit (NPU) delivering 2.3 tera operations per second (TOPS). This heterogeneous architecture provides a robust foundation for computer vision, voice recognition, and other AI applications, while also supporting real-time control.

For multimedia and connectivity, the board offers a comprehensive set of interfaces. HDMI 2.0, MIPI-DSI, and dual low-voltage differential signaling (LVDS) outputs support display development, while dual MIPI-CSI inputs enable camera integration for vision applications. Networking and expansion are equally versatile, with dual Gigabit Ethernet, USB 3.0, and an onboard Wi-Fi 6/Bluetooth 5.4/802.15.4 tri-radio module.

Accelerate development with comprehensive software support

The FRDM platform's hardware flexibility is matched by comprehensive software resources designed to streamline development across the entire processor range. NXP supports this by providing two software development paths, one for real-time MCUs and one for high-performance MPUs.

For MCU development, NXP provides the MCUXpresso suite of software and tools. This is a comprehensive suite for Cortex-M processors (such as the MCX C and MCX A) that includes the MCUXpresso integrated development environment (IDE), a VS Code extension, configuration tools, and a high-quality software development kit (SDK). This path is designed for real-time applications and supports familiar embedded IDEs, such as IAR Systems’ Embedded Workbench and Keil MDK.

For MPU development on processors like the i.MX 8M Plus, NXP provides robust support for Embedded Linux, including Board Support Packages (BSPs) for Yocto Project and Debian. To get started quickly, NXP offers GoPoint, a repository of pre-built, Linux-based demos and step-by-step guides for advanced applications, such as computer vision, AI, and multimedia.

To accelerate prototyping on the MCU side, NXP also offers the MCUXpresso Application Code Hub. This is a centralized repository of software examples and application demos developed by NXP experts and partners. The hub provides over 180 code examples spanning motor control, sensing, and AI. These examples are designed to work directly with FRDM boards, allowing an application prototype built on one FRDM MCU board to be migrated to another compatible MCU with minimal changes.

Conclusion

As embedded system requirements evolve and overlap, engineers need efficient ways to experiment with multiple processors and quickly prototype their ideas. The NXP FRDM platform’s modular hardware and shared software resources make this exploration practical, supporting everything from low-power MCUs through mid-range control to Linux-class, AI-enabled MPUs. By standardizing expansion and code reuse, it shortens the path from concept to working prototype while preserving flexibility as designs scale.