Together at Last: FPGA + RISC-V

The Icicle Kit is the first development board for the groundbreaking PolarFire SoC, the world’s first FPGA and Linux-capable RISC-V system in a single chip.

Whether you are developing cutting-edge applications in embedded machine learning, wired networking, or industrial automation, or simply exploring RISC-V and FPGAs, the Icicle Kit and its robust Mi-V ecosystem of tools are the perfect way way to get started.

Features & Specifications

• PolarFire SoC (MPFS250T-FCVG484EES)
  • 600 MHz clock
  • 1 x RV64IMAC core by SiFive
  • 4 x RV64GC core by SiFive
  • 254K logic elements non-volatile fabric
  • 784 x math block (18 x 18)
  • 4 x 12.7 Gbps SERDES
  • Secure boot
• Memory
  • 2 GB LPDDR4 x 32
• Storage
  • 1 Gb SPI flash
  • 8 GB eMMC flash or SD card slot (multiplexed)
• Networking
  • 2 x Gigabit Ethernet
• Expansion Interfaces
  • Raspberry Pi-compatible 40-pin header
  • mikroBUS socket
  • PCIe gen2
  • Micro USB 2.0 Hi-Speed OTG
  • 4 x UART (via single micro USB)
  • 2 x CAN
  • SPI
  • I²C
• Power
  • 12 VDC / 5 A barrel jack input
  • On/off switch
  • I²C power monitor measuring four power rails
• User Interfaces
  • 4 x User push button
  • 4 x User LED
  • 4 x Power status LED
• Programming & Debugging
  • UART via micro USB
  • Onboard JTAG connector or embedded FlashPro6 (multiplexed)
  • 52 x test points

Icicle Kit Block Diagram

PolarFire SoC

The Icicle Kit is based on Microchip’s PolarFire SoC (MPFS250T-FCVG484EES), which is a system-on-chip that combines the state-of-the-art PolarFire FPGA with a five-core RISC-V microprocessor subsystem by SiFive.

To quote the official PolarFire SoC documentation:

The PolarFire® SoC FPGA family delivers an unparalleled combination of low power consumption, thermal efficiency and defense grade security for smart, connected systems.

It’s the first system on chip (SoC) field-programmable gate array (FPGA) with a deterministic, coherent RISC-V CPU cluster and a deterministic L2 memory subsystem enabling Linux and real-time applications.

Built on the award-winning, mid-range, low power PolarFire FPGA Architecture, PolarFire SoC devices deliver up to 50% lower power than alternative FPGAs, span from 25k to 460k logic elements (LEs) and feature 12.7G transceivers.

The unique architecture of the PolarFire SoC combines the power of RISC-V and Linux with the determinism needed for real-time hardware applications. See Microchip’s PolarFire SoC brochure and overview for more information.

PolarFire SoC Block Diagram

Support & Documentation

• Kit overview
• User guide
• Schematics
• Layout
• PolarFire SoC brochure
• PolarFire SoC overview
• Latest Linux builds, bare-metal libraries, and documentation
• Technical support portal

Icicle Kit (Top)

Icicle Kit (Bottom)

Development Tools

The Mi-V ecosystem brings together tools and vendors tailored for the PolarFire SoC, including:

• OS: Yocto, BuildRoot, FreeBSD
• RTOS: FreeRTOS, Zephyr, and others
• Compilers: GCC, IAR, and others
• Tools: Renode, Libero

Free Libero Silver License

Developing on the PolarFire SoC Icicle kit requires a Libero Silver license, which is free of charge and valid for one year. Once that license has expired, you will be able to generate a new license each year for free.

Demo: Linux Quick Start

Linux development on the Icicle Kit does not require any closed source tools or familiarity with FPGA development tools. Here’s how to get started quickly:

1. Connect the Icicle Kit USB-UART port J11 to host machine.
2. Connect the 12 VDC power supply to the Icicle Kit and the SW6 switch to ON.
3. Use a serial terminal (e.g., Putty, ExtraPutty, minicom, screen, etc.) to open four connections to the four UARTs available through the J11 USB connector using these serial port settings:
   • 115200 baud
   • eight data bits
   • no flow control
   • no parity
4. Power cycle the board. You should see boot messages on two of the serial terminal sessions:
   • One terminal displays Hart Software Services boot messages.
   • Another terminal displays U-Boot and Linux boot messages and provides a Linux prompt.
5. In the terminal with the Linux prompt, log in with user name root and either no password or, in some cases, a password of microchip.

That’s it! You are now logged into Linux running on the Icicle Kit.

Development History

Icicle Kit is an evolution of HiFive Unleashed by SiFive and the accompanying HiFive Unleashed Expansion Board by Microchip. We worked closely with SiFive to integrate their RISC-V cores into PolarFire SoC and consolidate everything onto a single board.

HiFive Unleashed (right) and HiFive Unleashed Expansion Board (left)

Icicle Kit underwent several prototype iterations before arriving at the final design.

Icicle Kit