DAP Technology 1394, Руководство по эксплуатации

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Monitor
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Errors
The Errors box gives the user a quick indication of the existence of erroneous packets. It handles the
following kind of errors:
Data CRC error
All packets that have a data block and with an error detected in the data CRC are counted here. Note that
only packets that have a valid header (correct header CRC and valid tcode) can have a data block, and
thus packets with data CRC error are not counted as 'error' packets in the Packets section.
Hdr error (CRC or len.)
All packets that have a valid tcode, but a header CRC error are counted here. Also when the CRC could
not be calculated because the packet was to small, it will be counted here. These packets will always be
bigger than or equal to 8 bytes and will not be phy packets. They are counted as 'error' packets in the
Packets section.
Note that packets with invalid tcode have unknown header size, and thus the header CRC cannot be
calculated. Therefore packets with invalid tcode are counted separately (see below).
Acknowledge error
All packets of exactly one byte, but with an error in the inverse check, are counted here.
Packets < 8 bytes
All packets smaller than 8 bytes, but not exactly one byte (acknowledge packets) are counted here.
Invalid tcode in Hdr
Packets with invalid tcode (a tcode that is not allowed) are counted here. These packets will always be
bigger than or equal to 8 bytes and will not be phy packets. They are counted as 'error' packets in the
Packets section.
Note that packets with invalid tcode have unknown header length, and thus the header CRC cannot be
calculated.
Invalid Phy
All packets exactly 8 bytes (2 quadlets) long and with the second quadlet the inverse of the first quadlet
are considered phy packets. If the Analyzer detects such a packet with invalid information such that the
phy type is unknown, this count is incremented.
Invalid Acknowledge
All packets of exactly one byte with correct inverse check are considered correct acknowledge packets. If
the Analyzer detects such a packet with invalid (not allowed) acknowledge code, this count is
incremented.
Status
Here the number of bus resets is counted.
Bus Voltage
The Analyzer will measure the IEEE1394 bus voltage and display the value here in volts. The resolution is
0.1 volt.
5.3. Multi-bus Version
For multi bus analyzers, or when using the standalone Monitor (found in the tools menu), the monitor is
capable of showing counter values for multiple buses. A multi bus Monitor can look as follows: