HiFive Unleashed


Platform SiFive: SiFive brings the power of open source and software automation to the semiconductor industry, making it possible to develop new hardware faster and more affordably than ever before.

Microcontroller FU540
Frequency 1500MHz
Flash 32MB
Vendor SiFive


Please use hifive-unleashed ID for board option in “platformio.ini” (Project Configuration File):

platform = sifive
board = hifive-unleashed

You can override default HiFive Unleashed settings per build environment using board_*** option, where *** is a JSON object path from board manifest hifive-unleashed.json. For example, board_build.mcu, board_build.f_cpu, etc.

platform = sifive
board = hifive-unleashed

; change microcontroller
board_build.mcu = fu540

; change MCU frequency
board_build.f_cpu = 1500000000L


Debugging - “1-click” solution for debugging with a zero configuration.


You will need to install debug tool drivers depending on your system. Please click on compatible debug tool below for the further instructions and configuration information.

You can switch between debugging Tools & Debug Probes using debug_tool option in “platformio.ini” (Project Configuration File).

HiFive Unleashed has on-board debug probe and IS READY for debugging. You don’t need to use/buy external debug probe.

Compatible Tools On-board Default
FTDI Chip Yes Yes
QEMU Yes  
Renode Yes  


Name Description
FreeRTOS FreeRTOS is a real-time operating system kernel for embedded devices that has been ported to 40 microcontroller platforms
Freedom E SDK Open Source Software for Developing on the SiFive Freedom E Platform