The Implementing and Researching of BIT in Airborne Computer - Advanced Research on Computer Education, Simulation and Modeling - page 197

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compare result n bit (n is the allow error tolerance of the system n determined

by system's precision), the D/A channel is normal. Otherwise the channel is fault,
should be isolation from the system.
The system block diagram is show as fig 3

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Fig. 3. The flow chart of A/D 、 D/A channel test

3.3 The Serial Interface Test and Fault Isolation

The serial interface BIT test method is send & receive circle test method. In the sending
channel test, the settlement data would be sent by the serial interface, and the data
should be read by assistant BIT serial interface. Comparing the data read by BIT circuit
with the settlement data, according to the rule of the minority subordinated to the
majority, the interface can be judged to be normal or fault. If the interface is fault, it
should be reported and isolation from the system.
In the receive channel test, using the assistant BIT interface read the data at the same
time, according to the rule of the minority subordinated to the majority, the interface
can be judged to be normal or fault. If the interface is fault, it should be reported and
isolation from the system.
The system block diagram is show as fig 4

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Fig. 4. The flow chart of serial channel test

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