DAP Technology 1394, Руководство по эксплуатации

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Filter/Trigger
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Here you can select packet speeds. All packets with a speed of one of the selected speeds will be
skipped. Note that when the S100 speed is selected, the Phy SelfID packets will be skipped too. This
means that the topology can not be drawn in the Topology View of the Recorder, because the Phy SelfID
packets are needed for that.
Skip prefix-only packets
Here you can select to skip all prefix-only packets. And if you do not skip all, you can select to skip only
short prefixc-only packets.
Prefix-only packets are packets for which the Analyzer analyzer did not see any data. It only sees a prefix.
There are two situations this can happen:
· speed limitation
If for example some node is transmitting a packet at 400Mb/s and this node is connected to the
Analyzer with a slower speed node in between, then this 400Mb/s packet can not be repeated by this
slower node to the Analyzer. The Analyzer sees a packet but not the data. During the duration of the
whole packet a prefix will be detected.
These are mostly long prefixes, because all data is detected as prefix. To skip these kind of prefix-only
packets, you should skip all (short and long) prefix-only packets.
·
1394b status signalling
If all nodes are 1394b nodes, it is possible that a status event is embedded in a null-packet. These null
packets may by detected by the phy layer and the phy can signal a prefix to the link layer, without any
data. The result will be a short prefix-only packet.
This phy behaviour can not be disabled. Therefore, we added on option to be able to skip short
prefix-only packets. Because the status is embedded in nul-packets, those prefixes are usually very
short.
Skip events
In this box you can specify to skip some bus-events, the phy-interrupt event and external events. By
default these events will all be skipped.
When Arbitration Reset Gaps, Cycle Starts and especially Subaction Gaps are not skipped, be aware that
a lot of these events may be stored. This can increase the download time considerably.
Note that when these event are not skipped, they will show up in the
Packet View and also in the Time
View if you zoom far enough.
12.2.5. Packet sets
The Packet Sets tab is not available on
·
Stealth Series in Symbol Recorder mode
Each of the four basic sets (SetA, SetB, SetC and SetD) can be used for the record filter and or trigger
logic as described above. A Set defines a subset of all asynchronous and isochronous packets by
specifying packet types, packet speeds and optionally value conditions for one or more header and or
data fields.
A packet is said to 'fit' the Set if all specified conditions are met. Thus if the packet is of the specified type,
and the packet is of the specified speed, and the optional header and data fields conditions are met, then
the packet 'fits' the Set.
A Set page has the following parts:
· 'Primary Packets' or 'Phy Pakets' selection
·
'Primary Packets' box to select primary types
· 'Packet Speeds' box to select which packet speeds are included
· 'Header Values' box to specify optional header field conditions
·
'Data Values' box to specify optional data field conditions