Barry M. Cook

IEEE 1355 data-strobe links: ATM speed at RS232 cost

Abstract IEEE standard 1355 (1995) describes several transmission schemes for high-speed, low-latency data communications. One scheme, that employing Data-Strobe encoding, provides robust communications at up to about 200 Mb/s. The low-level protocols can be implemented with modest logic, as has been proved by the design of an interface in a low-end PLD. Consideration of the building blocks used shows similarities with the blocks used to implement RS232 transceivers. This paper compares the circuitry required to implement IEEE 1355 Data-Strobe links with that required for the ubiquitous RS232 modem connection standard and concludes that they are very similar. For approximately the same silicon cost as RS232, a data-strobe link can provide a communication channel with a performance comparable to that of ATM.

The I/O-Boards

This chapter provides the technical description of the system’s I/O-Boards and the CCSDS-Boards for telecommand decoding and telemetry encoding. The approach for these two OBC components is a common design for the printed circuit boards of both board types, just with differing chip population. Both of these board types are available with singleredundancy inside the OBC and are connected to the two OBC Processor-Boards via cross coupled SpaceWire links running RMAP protocol. A key characteristic is that although implementing completely different functionalities both boards are based on the same 3U printed circuit board, FPGA chip and I/O driver ICs design.