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Bridging of bidirectional streams of characters from Ethernet to SpaceWire;
The ability to support up to eight concurrently-active SpaceWire ports, depending on the configuration
purchased;
The transmit speed of the links can be set at up to 400Mb/s in steps of 1Mb/s or less;
The receive speed of the links is in excess of 400Mb/s;
Software is provided for the manual and scripted generation of SpaceWire traffic, together with a C-
language programming API for automated testing.
2.4
DSI Options
A Diagnostic SpaceWire Interface can be supplied with firmware that provides additional optional features.
Detailed information about these options can be found in section 7, “DSI Option Details”.
2.4.1
ER - Event / Error Reporting
Tokens defined as errors, that would normally be hidden (typically resulting in a link reset) and replaced by (at
most) an EEP character, can be made visible to the user. Correct, but normally hidden tokens (such as flow-
control tokens) can also be transferred to the user.
2.4.2
EW- Event / Error Waveforms
Each SpaceWire port has an associated waveform store that captures transmit and receive wire signals for that
port. Waveform captures can be triggered on a wide variety of events on that and/or other ports. It is possible,
for example, to capture wire signals for all ports after a trigger signal on one port.
Triggers include all error conditions, received data, lifting of the synchronised outputs barrier, signals on the
external SMA connectors, and user-inserted flags in the transmit data stream.
2.4.3
EI - Event / Error Injection
SpaceWire tokens that are not normally generated, because they are defined as errors, can be explicitly
inserted into the data stream:
Parity error between tokens
ESC-EOP - escape end-of-packet
ESC-EEP - escape error-end-of-packet
ESC-ESC - escape escape
Idle periods - when D and S remain constant. An extended idle period (greater than the SpaceWire
disconnect timeout, which is nominally 850 ns) should trigger a SpaceWire timeout response.
These error injection functions allow the user to determine the behaviour of SpaceWire components under
controlled error conditions.
The EI option also allows the flow-control behaviour of the SpaceWire state-machine to be altered to provoke
behaviour and errors relating to flow-control. For instance, flow-control tokens may be withheld, either partially
or completely, to explore a device’s handling of low flow-control credit. Alternatively, too many flow-control
tokens can be issued, which should eventually result in a SpaceWire error condition.