Open hardware baseboard for PolarFire SoM and other CM4 form-factor devices

Focus on modularity and component reuse in software and hardware is prevalent at Antmicro as a means to improve vertical integration, and in turn, accelerate prototyping and get customer projects to market faster. In line with this notion, for years now we have been building an ever growing open hardware ecosystem by releasing open source baseboard designs based on cutting-edge COTS (Commercial Off-The-Shelf) technology such as our popular Jetson Orin Baseboard. Antmicro’s easily customizable open hardware is always complemented by a collection of compatible accessories targeting particular application areas, e.g. computer vision, and, most importantly, the matching, equally open source software, AI tools and workflows to provide end-to-end development options for like-minded customers reaching to industries traditionally dominated by closed and proprietary solutions that often become a crucial obstacle in both security engineering and fast time-to-market.

With this article, we are introducing Antmicro’s open source CM4 Baseboard intended for development of versatile commercial applications utilizing the popular CM4 form factor. While originally designed to work with Antmicro’s recently introduced PolarFire SoM, it is compatible with other modules in the form factor and pinout of the Raspberry Pi Compute Module 4.

The PolarFire SoM, featuring a powerful RISC-V SoC + FPGA combo from Microchip, provides a platform with an open and extensible ISA combined with the ability to use a range of soft CPU cores in the FPGA, making it easy to redesign systems based on real life feedback without requiring the physical replacement of hardware. By exposing the SoM’s interfaces, the CM4 baseboard can serve as a development kit for fast integration and testing of the SoM as part of larger systems and for building PoC setups – from edge computing kiosks that can be updated through the onboard WiFi to CubeSat-spec satellite modules.

The CM4 Baseboard is also intended as a starting point for building complete edge AI devices, as Antmicro can adjust it to your needs, e.g. by miniaturizing the board to fit your desired form factor, or by limiting the I/O to required interfaces only. Other possibilities include hardening the board for protection against radiation or against extreme temperature conditions and fluctuations, reflecting the typical needs of space-faring hardware.

Antmicro CM4 Baseboard – feature overview

The Antmicro CM4 Baseboard is compact in size at 107mm x 68mm – as small as half of the footprint of the original Raspberry Pi Compute Module 4 IO board.

The baseboard is capable of supplying more power to the Compute Module than required by the Compute Module 4 IO board in order to support the more high-performance designs like the PolarFire SoM FPGA, and can be powered via:

• Power over Ethernet
• USB-C PD
• a DC locking connector.

The design also supports fast PCIe x4 NVMe storage to fully utilize the capabilities offered by the PolarFire SoM.

Just like other boards in the Antmicro open hardware ecosystem, the CM4 baseboard exposes a Dual CSI connection that supports a variety of our open source video accessories:

• Composite Video (CVBS) to MIPI CSI-2 bridge
• CSI Adapter for integration of FRAMOS camera modules
• GMSL Serializer and Deserializer boards
• HDMI to MIPI CSI-2 bridge
• OV9281 Dual Camera board
• SDI to MIPI CSI-2 bridge
• SDI to MIPI CSI-2 converter based on the Lattice CrossLink-NX FPGA.

For more interactive video-related needs, the board features a display adapter expansion connector. The connector exposes MIPI DSI output, power, and touchscreen interface. It can be used for connecting a wide variety of displays by means of adapter boards. An example implementation of such an adapter is Antmicro’s open hardware LVDS LCD adapter.

For fast prototyping, the board exposes a GPIO expansion connector, including I2C, SPI and UART interface options. In addition, the NFC controller on the board (with external antenna) is suitable for applications that require access control, asset tracking, etc.

The CM4 Baseboard also exposes other common IO interfaces:

• 1 Gbit Ethernet
• HDMI 2.0
• USB-C HS DRP
• microSD card slot
• 2x QWIIC for connecting additional sensors.

Below you can explore an interactive block diagram of the baseboard represented in Antmicro’s System Designer framework:

Design and prototype customized complex devices with Antmicro’s ecosystem

The CM4 Baseboard is a universal choice for a wide variety of applications such as in CubeSats, where the range of onboard communication features can be used to automatically deliver content to end users. It is easy to implement complex and powerful designs based on the Polarfire SoM, and the Raspberry Pi Compute Module 4-compatible solution is also compatible with other parts of Antmicro’s open source ecosystem, from computer vision accessories to software solutions including remote fleet management and Over-the-Air updates with smart delta packages, and AI services.

Find out how your use case can benefit from the scalability, transparency and full design control offered by Antmicro’s open source engineering approach, end-to-end development services as well as the tools, CI-based workflows and off-the-shelf devices comprising our open source portfolio. Feel free to contact us at contact@antmicro.com or take a minute to explore our interactive System Designer with its ever growing library of hardware components, hundreds of CI simulation testing options at designer.antmicro.com.