Board keeps watch over SpaceWire links

The Dynamic Engineering SpaceWire Break-Out (DESWBO) monitors the signals of a single SpaceWire link. The board has two 9-pin MDM connectors to facilitate inline monitoring of both sides of a SpaceWire link. DESWBO is designed to detect and decode bit sequences.

Signals are issued indicating what types of characters are passing between nodes as well as the contents of data and timecode characters.

A running count of flow control credits for each node is calculated by the DESWBO by monitoring FCTs and N-character occurrences.

The LVDS signals from each node are buffered to the opposite node and monitored by an FPGA.

The FPGA contains the equivalent of two SpaceWire receiver modules that decode the SpaceWire signals, and extract the various data and control characters.

The DESWBO is tested with a special version of the PCI-SpaceWire with the ability to insert errors under software control.

Normal and error conditions are tested on each unit as part of the ATP.