Overview

The SpaceWire-to-GigabitEther is a crucial interface that enables seamless communication between SpaceWire networks and standard PC software through Gigabit Ethernet. This enabling technology allows users to efficiently send and receive SpaceWire packets to and from a SpaceWire node or router connected to their device. The accompanying C++ class library empowers users to develop custom applications that leverage the device's capabilities, including the implementation of Remote Memory Access Protocol (RMAP) to interact with RMAP Target nodes across the SpaceWire network.

While this interface has not been flight qualified, it was originally designed for scientific experiments and ground tests involving SpaceWire-based data acquisition systems.

Two Versions Available

There are two variants of the SpaceWire-to-GigabitEther interface:

• Open-source Version: This version utilizes the ZestET1 board from OrangeTree, integrating SpaceWire Open IP developed by Shimafuji Electric and Osaka University. It allows a single TCP/IP connection to one external SpaceWire port.
• Product Version by Shimafuji Electric: In contrast, this variant includes an internal SpaceWire router with four micro-Dsub (MDM) external SpaceWire ports and supports higher transmission frequencies (up to 200MHz), compared to approximately 130MHz for the open-source version.

Both versions function as a TCP server, ready to accept connections from client PCs running user programs. When inactive, they return to the listening state to await reconnections.

Key Features

• Performance: The open-source SpaceWire-to-GigabitEther achieves data transfer rates of up to 95 Mbps (maximum) when operated at 125 MHz. In comparison, the Shimafuji version can reach ~160 Mbps over a 200-MHz link, operating with approximately 80% efficiency due to the SpaceWire standard's data/control flag and parity.
• Accessibility: Extensive documentation is available to guide users regarding installation, usage, and technical specifications:
  • User Guide for Open-source SpaceWire-to-GigabitEther
  • Hardware Specifications for Shimafuji's SpaceWire-to-GigabitEther

Typical Usage

Utilizing the SpaceWire-to-GigabitEther bridge makes it possible to control SpaceWire nodes from PC software and facilitate data transfers. This engaging piece of technology opens up numerous possibilities for data management and communications in various applications.

FPGA and Circuit Information

Users can access the latest VHDL project and compiled bit files for programming the ZestET1 FPGA:

• VHDL Project: Download Here
• Compiled Bit File: Download Here

The interface board circuit can be found at: Circuit Diagram.

Updating the FPGA IP Core

Updating the FPGA core of the SpaceWire-to-GigabitEther can be completed easily through Ethernet without needing a JTAG connection, utilizing the control panel software provided by OrangeTree.

For more details, consult the User Guide for comprehensive instructions.