By John McHale

COLORADO SPRINGS, Colo. - Engineers at Aeroflex Inc. are supporting a networking standard for satellite applications called SpaceWire that can move data at 2 to 400 megabits per second.

Aeroflex Colorado Springs in Colorado Springs, Colo., is entering the SpaceWire market with a SpaceWire Protocol Handler and a SpaceWire Physical Layer transceiver.

SpaceWire is a standard governing serial communication between satellite components. The protocol is self-managing and provides a high-speed, low-power serial interface while offering a simple user interface.

The standard supports data rates of 2 megabits per second to 400 megabits per second over 10 meters of cable. Originally developed by the European Space Community (document ECSS-E-50-12A), SpaceWire marries IEEE-1355 with a low-voltage differential signaling (LVDS) physical layer.

“Aeroflex Colorado Springs saw the benefits of the SpaceWire standard used in numerous European satellites; building a product family was our next step,” says Anthony Jordan, director of standard products at Aeroflex.

“The benefits are straightforward,” he continues. “SpaceWire is a simple protocol, a simple user interface (FIFO) with high data rates and low power using LVDS, has point-to-point full duplex and supports networked systems via routers”.

NASA experts also are supporting SpaceWire, and are looking to adapt it for U.S. satellite programs, Jordan says. It is considerably faster than MIL-STD-1553, and is better received than IEEE 1394 Firewire, he adds.

SpaceWire not only is faster than Firewire, which performs at 100 megabits per second, but also is more easily integrated into space applications due to its simplicity, Jordan says.

Firewire was chosen for the NPOESS program and was considered the standard of the future for satellites, but SpaceWire is overtaking it, Jordan says.

Aeroflex’s UT200SpW02 Protocol Handler manages the character level SpaceWire protocol. It takes the serial bits and translates them into words, Jordan says.

Data rates range from 2 to 200 megabits per second with a 9-bit transmit and receive FIFO user interface, 2.5-volt core supply voltage, and 3.3 volt I/O supply voltage.

The UT200SpW02 is designed to withstand 300 kilorads upsetting charge particle strikes to 40 MeV-cm2/mg, and is single-event latchup immune to greater than 120 MeV-cm2/mg. The Protocol Handler comes in a 208-pin cerquad flatpack as a QML Q and V compliant part, Aeroflex officials say.

The LVDS physical layer for the Protocol Handler is the UT200SpWPHY01 Physical Layer Transceiver designed to handle timing issues associated with the SpaceWire data/strobe encoding scheme.

The UT200SpWPHY01 supports data rates as fast as 200 megabits per second with data/strobe transmit skew less than 400 picoseconds. This device basically drives the signal over the physical SpaceWire layer, which is a twisted-pair cable, Jordan says.

The UT200SpWPHY01 has a 3.3-volt power supply and cold spare on all pins, company officials say. Electro static discharge performance of LVDS inputs/outputs is greater than 8,000 volts HMB.

The UT200SpWPHY01 is designed to withstand 300 kilorads, upsetting charge particle strikes to 40 MeV-cm2/mg and is single-event latchup immune to greater than 100MeV-cm2/mg. The UT200SpWPHY01 is packaged in a space-saving 28-pin flatpack and will be offered as a QML Q and V compliant part.

The UT200SpW02 SpaceWire Protocol Handler will be available as a Standard Microcircuit Drawing (SMD) number, QML Q and V qualified. Prototypes are available now.

The UT200SpWPHY01 Physical Layer Transceiver will be available as an SMD, QML Q and V qualified. Prototypes and production units will be available later this year. For more information contact Aeroflex online at www.aeroflex.com/SpaceWire.