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DSI Option Details
The Diagnostic SpaceWire Interface may be specified with the following options: Event / Error Reporting (ER);
Time Tags (TT);
Event / Error Waveforms (EW);
Event / Error Injection (EI);
Synchronized Outputs (SO);
Controlled Outputs (CO);
Output Disable (OD); and
Output Enable (OE);
These are described in greater detail in the following sections.
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Option ER – Event/Error Reporting
Normally, only data and EOP/EEP characters are seen by the user. Other sequences and tokens/token sequences
are hidden, some because they cause error conditions and result in the link being reset (and possibly also
generating an EEP character).
This option allows selected events to be seen by the user for diagnostic purposes. In the case of error events,
further action may be taken if the EI (Error Injection) option is also installed.
Events reported by this option are when:
Time codes are received;
Flow-control tokens are received;
ECSS errors, ESC-ESC, ESC-EOP, ESC-EEP, Timeout, Parity error, are received.
We suggest that familiarisation with this feature is gained with the
SpWIO
program before using it from a C
program.
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Option TT – Time Tags
An internal quartz crystal controlled oscillator feeds a counter that represents the time, to a resolution of less
than 2 ns, from power-up of the unit. That time can be captured and reported to the user each time an enabled
event occurs. This option allows time capture on the receipt of one or more of these events:
the first byte of a packet;
intermediate bytes of packets;
the end-of-packet marker, EOP;
the error-end-of-packet marker, EEP;
SpaceWire time codes;
flow-control tokens, FCT;