Astrobe for FPGA RISC5 v7.2

Embedded Project Oberon


Astrobe for FPGA RISC5 is a free Windows IDE which enables you to program embedded software using the Oberon language. The applications execute on an embedded real-time subset of the Project Oberon Operating System running on a Xilinx FPGA development board. An example is Digilent's Arty S7-50 board, shown above, fitted with an Opus-Two microSD-card adapter and RTC module connected to PMOD sockets, running the Oberon AutoCAD slide viewer.

The Project Oberon system is described in an article titled Oberon System Implemented on a Low-Cost FPGA Board published in Issue 91, Second Quarter 2015, of Xilinx's Xcell Journal.

Highlights of the Astrobe Embedded Project Oberon system are:

Astrobe Integrated Delopment Environment (IDE)

The Astrobe IDE allows you to edit and cross-compile your RISC5 Oberon programs on Windows. Once the code compiles without errors the Upload menu command transfers one or more executable RISC5 (*.rsc) files using the fast 115200 baud RS232 connection to the target FPGA board for execution. No static linking step is needed - all modules are automatically dynamically linked and loaded at runtime.

The Astrobe for RISC5 IDE is identical to the commercial version that is used to develop embedded software for the ARM Cortex-M3, M4 and M7 microcontrollers. Astrobe's features make this a very convenient system for developing embedded RISC5 Oberon software. Highlights are:

Embedded Project Oberon

The compiled applications produced by Astrobe can be executed on a subset of the complete Project Oberon OS i.e. just the Kernel, loader, filesystem, SPI, RS232 and SD card support. This is referred to as Embedded Project Oberon. All of the development can be done on Windows so the higher-level layers of Project Oberon OS with its user-interaction features: GUI, display, VGA, mouse, keyboard, compiler, editor etc. are not required on the target FPGA system.

Interactive execution of the programs can be controlled by the Astrobe Terminal connected to the development board by a 115200 baud serial link. Download the Embedded Project Oberon version of the document How to use the Oberon System for more details.

Supported FPGA Development Boards

The reduced memory footprint of Embedded Project Oberon means it is possible to run RISC5 Oberon applications on the latest Xilinx FPGA devices (with 176 KBytes or more of usable internal BRAM) at clock speeds up to 50Mhz with no need for any external RAM. As well as the Arty form-factor boards shown above, Embedded Project Oberon has been implemented on breadboardable systems e.g. Digilent's Cmod A7-35T:

 The current list of Xilinx FPGA development boards supported with Astrobe v7.2 and Embedded Project Oberon is:

Board Arty A7-100T Nexys A7-100T Arty A7-35T    Cmod A7-35T    Arty S7-50    Arty S7-25 Cmod S7-25   
Family Artix-7 Artix-7 Artix-7 Artix-7 Spartan-7 Spartan-7 Spartan-7
Part XC7A100T XC7A100T XC7A35T XC7A35T XC7S50 XC7S25 XC7S25
Manufacturer Digilent Digilent Digilent Digilent Digilent Digilent Digilent
Clock 40 MHz 40 MHz 40 MHz 40 MHz 40 MHz 40 MHz 40 MHz
Global Data +
Code +
Stack Data
480 KB 480 KB 160 KB 160 KB 160 KB 144 KB 144 KB
Dynamic Data 32 KB 32 KB 32 KB 32 KB 32 KB 32 KB 32 KB
GPIO 32 8 32 18 32 32 18
SPI 3 2 3 2 3 3 2
I2C 1 1 1 1 1 1 1
LEDs 4 8 4 2 4 4 4
Buttons 4 4 4 2 4 4 2
Switches 4 8 4 - 4 4 -
Available Now Now Now Now Now Now Now


The complete Astrobe for FPGA RISC5 software system consists of:

Request your copy free of charge via download here.

Technical Support

Ask any questions about this system and find the latest news, additional examples and implementation details on the Astrobe for FPGA RISC5 Forum.