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Chapter 6
Counter/Timer Features
The counter/timer circuitry on the board provides the clocking circuitry used by the A/D and
D/A subsystems as well as several user counter/timer features. This section describes the
following user counter/timer features:
• Units
• C/T clock sources
• Gate types
• Pulse types and duty cycles
• Counter/timer operation modes
Units
DT3034 boards support four user 16-bit counter/timer units (called counters); counters are
numbered 0, 1, 2, and 3.
Each counter accepts a clock input signal and gate input signal and outputs a clock output
signal (also called a pulse output signal), as shown in Figure 28.
Clock Input SIgnal
(internal, external, or
internally cascaded)
Counter
Pulse Output Signal
Gate Input Signal
(software or external
input)
Figure 28: Counter/Timer Channel
Each counter corresponds to a counter/timer (C/T) subsystem. To specify the counter to use
in software, specify the appropriate C/T subsystem. For example, counter 0 corresponds to
C/T subsystem element 0; counter 3 corresponds to C/T subsystem element 3.
C/T Clock Sources
The following clock sources are available for the user counters:
• Internal C/T clock
• External C/T clock
• Internally cascaded clock
Refer to the following subsections for more information on these clock sources.
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