
9 VBAT-PB VME bus anomaly trigger
violations of the important VMEbus arbitration, data transfer and interrupt
protocols.
The VBAT can be used as a partial "non-compliance detector.", as it uncovers
design, manufacturing and field-failure-induced flaws in portions of the bus
interface circuitry of both VME masters and slaves. I t will also uncover a wide
variety of hardware problems, originating in other parts of a VME board, that
indirectly cause illegal bus activity. It does this by watching the boards in
question during real-world use in the actual system configuration.
A VBT-325 with a VBAT-PB can for example help determine why a board
from a particular manufacturer does not function properly in a system from
another
manufacturer.
Example of violation found
Below is an example of a "RULE 3.10 VIOLATION", i.e. the VBAT-PB
recognizes a master illegally rescinding BBSY* before the bus grant goes high,
often caused by ringing on BBSY* as shown.
BR2* \
i
BG2* \
.
i
B B S Y * - - - - - \ _ ) - \
TRIG*
\
t
Violation!
BBSY* released
before BG2* negated.
Figure 40. Rule 3.10 violation
Mask violations
The VBAT-PB
may be programmed to mask out "innocent" VMEbus
violations, i.e. violations that occur
sporadically, and generally do not restrict
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Содержание VBAT-PB
Страница 15: ...x i v 1 1 I 1 1 I I i i I I 1 I I 1 I 1 I I ...
Страница 23: ...1VBT 325 Product overview 8 V B T 3 2 5 User s Manual V M E T R O ...
Страница 125: ...8 Trace examples 110 V B T 3 2 5 User s Manual V M E T R O ...
Страница 144: ...9 VBAT PB VME bus anomaly trigger ITP40 I GND VMETRO V B T 3 2 5 User s Manual 1 2 9 ...
Страница 159: ...1 1Jumper settings 144 V B T 3 2 5 User s Manual V M E T R O ...
Страница 181: ...16 Simulator for PC 166 V B T 3 2 5 User s Manual V M E T R O ...