• lowRISC with run/step debugging via JTAG and GDB
    Release version 0.6, released October 2018
    This release updates the Rocket IP to March 2018 and includes compressed instructions and JTAG debugging conforming to the RISCV Debug Specification with custom JTAG DTM (see JTAG internals for details). The root filing system is updated to use the mostly upstreamed Debian repository and the peripheral data path widths are increased to 64-bits for better performance.
  • lowRISC with 100MHz Ethernet and Network filing system access
    Release version 0.5, 01-2018
    This preview release provides a complete Ethernet reference design, tools, and NFS root capability. This includes the ability to arp, ping, ssh client and server, mount remote NFS disks, and run a full multi-user system (within the available RAM and FPGA CPU performance limitations) The SD-card interface is promoted to a Rocket peripheral to boost performance. The human interface (keyboard and VGA compatible text display) are integrated as the default Rocket console. We continue to support the Nexys4 DDR FPGA platform, only the Minion is omitted. The tutorial outlines the build procedure and forthcoming releases that we are planning.
  • lowRISC with tagged memory and minion core
    Release version 0.4, 06-2017
    This release provides a more complete prototype of tagged memory implementation. This includes the ability to define tag propagation rules and policies that control when encountering unexpected tags should raise exceptions. These features have been incorporated into the Rocket core. An optimised tag cache has also been developed in order to minimise any additional main memory traffic from the use of tags. A simple “minion” core is added to provide an SD-card interface. This system also supports a keyboard and provides a VGA compatible text display. We continue to support the Nexys4 DDR FPGA platform. The tutorial outlines the build procedure and forthcoming releases that we are planning.
  • lowRISC with a trace debugger
    Release version 0.3, 07-2016
    In this code release we present a first prototype of the lowRISC debug infrastructure. It extends the untethered lowRISC system with the means to control the system, load programs and trace the software execution. The tutorial outlines the debug system and the future directions we are planning. It demonstrates debugging with the RTL simulation and on the Nexys4 DDR FPGA board.
  • Untethered lowRISC
    Release version 0.2, 12-2015
    A code release providing a standalone lowRISC by untethering the Rocket chip. Cores in the original Rocket chip relies on a companion processor to access I/O devices. This release repalce this companion core with actual FPGA peripherals. A tutorial explains how to use this code release and explains the underlying structural changes.
  • lowRISC with tagged memory
    Release version 0.1, 04-2015
    A code release builds on the Rocket RISC-V implementation to offer support for tagged memory (see the release blog post). We’ve put together an extensive tutorial on how to use this code release as well as documenting many of the changes made.


Our first memo describes our plans for tagged memory and minion cores in lowRISC.


Over the summer of 2016 we hosted a group of interns, kindly sponsored by IMC Financial Markets who worked on adding custom acceleraors for video decoding to the lowRISC platform. This work resulted in the creation of several documents:

Although now over, you may be interested in our project idea list for Google Summer of Code 2015 and for GSoC 2016.