ADLINK ACL-8112 Series - Manual (Page 50)

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• Operation Theory
5
Operation Theory
The operation theory of the ACL-8112 card is described in this chapter. The
function description include the A/D conversion, D/A conversion, digital I/O
and counter / timer. The operation theory can help you understand how to
manipulate or program the ACL-8112.
5.1 A/D Conversion
Before programming the ACL-8112 to perform an A/D conversion, you need
to understand the following issues:
•
A/D conversion procedure
•
A/D trigger mode
•
A/D data transfer mode
•
Signal Connection
5.1.1 A/D Conversion Procedure
An A/D conversion is initiated when a trigger source is triggered, the A/D
converter will start to convert the signal to a digital value. The ACL-8112
provides three trigger modes, see section 5.1.2.
During an A/D conversion, the DRDY bit of the A/D data register is cleared to
indicate the data is not ready. After a conversion is completed, the DRDY bit
will return a low (0) signal. This indicates users now can read the converted
data from the A/D data registers. Please refer section 4.2 for the A/D data
format.