RTAX-S Goes to Mars
First Low-Power FPGA Heads to Red Planet
The Phoenix spacecraft includes a Meteorological Station (MET), provided by the Canadian Space Agency.
MDA,
a leading provider of robotic space systems, led construction of the
MET instrument and has integrated Actel's one-million-gate RTAX1000S-CQ352
device into the instrument subsystem. The subsystem is used to acquire,
process, and transmit temperature and pressure data to scientists and
researchers back on Earth.
The Phoenix mission will study the history of water and habitability potential in the Martian Arctic's ice-rich soil. The Phoenix spacecraft includes the MET built by MDA, which will record the daily weather of the Martian northern plains using temperature and pressure sensors. Once the Phoenix arrives on Mars, the MET instruments will be used constantly in surface operations, which are expected to last 150 days. These instruments are central to scientific exploration on Mars, providing the essential tools scientists need to learn more about the Martian climate and geology and determine whether life has ever existed. The MET instrument will contribute to the success of the Phoenix mission.
The MET instruments operate on a combination of battery power and solar energy. Because sunlight in the Martian polar region is even weaker than at its equator, all systems and their components must feature extremely efficient power management. Actel's antifuse-based technology combines radiation tolerance with the industry's lowest power, enabling it to withstand the rigorous environments of space flight and exploration.
To learn more about the Phoenix Mission, visit phoenix.lpl.arizona.edu.
SpaceWire Clock Recovery Logic Implementation
SpaceWire is a high-speed data link standard intended to meet the needs of future high-capability, remote sensing instruments in space missions.
SpaceWire provides a unified high-speed, data-handling infrastructure for connecting sensors, processing elements, mass-memory units, downlink telemetry subsystems, and Electrical Ground Support Equipment (EGSE). SpaceWire uses a Data-Strobe (DS) encoding scheme that encodes the transmission clock with the data into Data and Strobe so that the clock can be recovered by simply XORing the Data and Strobe lines together.
Data-Strobe
Encoding
The Data signal (D) follows the data bitstream—high when the data bit is 1 and low when the data bit is 0. The Strobe signal (S) changes state whenever the Data does not change from one bit to the next.
One of the challenges when implementing SpaceWire in an FPGA is the implementation of the SpaceWire clock recovery circuit, which requires minimum timing of propagation delays. Using Actel's block methodology, the SpaceWire clock recovery circuit can be implemented and analyzed for minimum delay reliably in the RTAX-S device. The SpaceWire clock recovery circuit block can then be imported into the main design with identical timing delays.
When considering implementation of SpaceWire in an FPGA, the designer should make sure that the FPGA supports the LVDS I/O standard. Actel RTAX-S supports multiple I/O standards, including LVDS, which allows implementation of SpaceWire and other blocks with different I/O standards in the same FPGA.
