3 Functional description
Start M i d d l e
End
0% 2 5 % 5 0 % 7 5 % 1 0 0 0 /
Figure 13. Five trigger positions in the trace buffer can be selected.
Note that the trigger may occur before the trace buffer has been filled
completely ahead of its specified trigger position. I n such cases the trace buffer
will be only partly filled before the trigger. (Imagine if the second sample
collected was the trigger, and the trigger position was 50%, then 16K-1 cells in
the first part of the trace buffer will be empty.)
Note also that if the trace is not completely filled
after
trigger and then halted
manually (possible in all cases except End of Trace), the unused post-trigger
portion of the trace buffer may contain valid pre-trigger samples from the
previous "round" of sampling (remember, the trace buffer is circular). If this is
the case, these samples will be shown since they may contain useful
information.
Statistics Counters
When the VBT-325 is used for statistical purposes rather than for storing
samples in the trace buffer, the bank of counters will be incremented according
to the values programmed into the word recognizers.
VMEbus T h e r e is a 20-bit counter attached to each of the word recognizers, as well as a
similar counter for each of four VMEbus Bus Level detectors, for a total of
eight statistics counters. In addition, there is a ninth counter used for counting
the total sample count. For VMEbus statistics, these counters are used to
provide histograms of four user-defined events at the same time as the
distribution of VMEbus traffic among the four bus levels are shown. There are
also statistics functions that use pre-defined event patterns to provide direct
readout of e.g. Bus Utilization.
VSB/SCSI/P2 F o r the P2 part there is a 20-bit counter attached to each of the word
recognizers. In addition, there is a fifth counter used for counting the total
sample count. These counters are used to provide histograms of four user-
defined events on VSB, SCSI or P2 bus.
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User's Manual
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Summary of Contents for VBAT-PB
Page 15: ...x i v 1 1 I 1 1 I I i i I I 1 I I 1 I 1 I I ...
Page 23: ...1VBT 325 Product overview 8 V B T 3 2 5 User s Manual V M E T R O ...
Page 125: ...8 Trace examples 110 V B T 3 2 5 User s Manual V M E T R O ...
Page 144: ...9 VBAT PB VME bus anomaly trigger ITP40 I GND VMETRO V B T 3 2 5 User s Manual 1 2 9 ...
Page 159: ...1 1Jumper settings 144 V B T 3 2 5 User s Manual V M E T R O ...
Page 181: ...16 Simulator for PC 166 V B T 3 2 5 User s Manual V M E T R O ...