Exciting news has emerged for RISC-V enthusiasts: Raspberry Pi has announced support for the open ISA with the release of the Pico 2 and the company's latest microcontroller, the RP2350.

Introducing the Pi Pico 2

The newly launched Pi Pico 2, which recently arrived at our seaside office, is available for just $5. According to the Raspberry Pi team, it maintains backward compatibility with previous versions, both in terms of hardware and software. The on-chip memory has been increased to 520KB, and there’s also 4 MB of on-board QSPI flash. The standout feature, however, is the inclusion of two RISC-V Hazard3 CPU cores, which are sure to catch the eye of both enthusiasts and developers.

Flexible CPU Choices

The Hazard3 cores aren’t mandatory. At boot time, users can opt to run either the pair of included Arm Cortex-M33 cores or the Hazard3 cores, both operating at 150 MHz. For those feeling adventurous, there’s even the possibility of running one RV core and one Arm core simultaneously.

Hazard3, an open-source design, is a lightweight three-stage in-order RV32IMACZb* machine, supporting the 32-bit RISC-V ISA with hardware-based multiplication, division, atomic instructions, bit manipulation, and more. It offers a glimpse into what might become a standard for architectural experimentation.

Comments from Eben Upton

Eben Upton, Raspberry Pi’s founder, expressed excitement about the new development: "RISC-V is an exciting development for us. Our goal is to provide software developers with a stable and well-supported environment to experiment with a different architecture. We’re particularly enthusiastic about the Hazard3 open-hardware core, developed by our ASIC engineer Luke Wren in his spare time."

Upton also mentioned the potential for RISC-V to offer a high degree of configurability for SoC designers and a valuable platform for researchers.

Security and Performance Enhancements

Security has been a focal point for this release, with the Raspberry Pi team incorporating a comprehensive security architecture into the new microcontroller. This includes Arm TrustZone for Cortex-M, signed boot, 8KB of antifuse OTP for key storage, SHA-256 acceleration, a hardware TRNG, and fast glitch detectors. There’s also a secure boot ROM, making the RP2350 and Pico 2 attractive options for professional users.

On the performance side, the Pico 2 has upgraded from two Cortex-M0+ cores to a pair of Cortex-M33 cores, each featuring an FPU and DSP. This enhanced performance opens the door to a range of new applications for both hobbyists and professionals, including music synthesis.

Price and Availability

While the Pico 2 is priced slightly higher than its predecessor—at $5 compared to $4—it offers significant upgrades in processing power and security features. However, connectivity options are somewhat limited, as a Wi-Fi version is not yet available, though it’s expected later in the year.

Acquiring a Pico 2 might be challenging initially, as Upton noted that the launch would be "shallowly stocked," with more units becoming available in the coming weeks. The price increase is partly due to the cost of the platform and the slightly more expensive RP2350 chip.

The Future of Raspberry Pi Pico

The Raspberry Pi Pico 2’s introduction of RISC-V in the form of Hazard3 cores makes it an intriguing option for both hobbyists and industry users. While the microcontroller business represents only a small percentage of Raspberry Pi's overall revenue, its growing volume is noteworthy.

It will be interesting to see how customers respond to these new features and the added flexibility that RISC-V offers.