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8-5. Detail of COMPARATOR Functions
Output of the detected condition from five COMPARATORs for the PULSE COUNTER and two COMPARATORs for the
DIFFERENTIAL COUNTER are connected to the following functional circuit and, thus, allows control according
to the user specification.
Output of
①
Through-output circuit
③
④
detection
②
Each COMPARATOR
Level input
Output of INT signal
Latch circuit
Edge input
Suppressed output
Output of STATUS3 signal
(Note)
①: INT MASK Circuit
This circuit masks output from the COMPARATOR at its exit.
You can specify separate levels of masking for each comparator on the PULSE and DFL counters.
This circuit is turned on or off by the INT MASK command.
As one of the special commands, it provides real-time, fine-tuned control of the masking.
②: LATCH TYPE Switch Circuit
This circuit is used for selecting a latch trigger type when detection by the COMPARATOR is latched
before it is output.
The latch type selected commonly applies to five comparators on the PULSE COUNTER.
Likewise, the type selected applies commonly to two comparators on the DIFFERENTIAL COUNTER.
You can differentiate the latch type between the PULSE COUNTER and the DIFFERENTIAL COUNTER.
Latch-output reset condition varies according to the trigger type as described in the following.
・When the level latch is selected:
When output of the COMPARATOR detection is not taking place, reading the STATUS3 PORT resets the
output (returns to the initial state).
・When the edge latch is selected:
Reading the STATUS3 PORT necessarily resets the output.
This circuit is turned on or off by the PULSE or DFL COUNTER INITIALIZE Command.
③: INT OUTPUT TYPE Switch Circuit
This circuit is used for selecting whether the COMPARATOR detection is to be output as it is (through)
or after latch.
The output type selected commonly applies to the five comparators on the PULSE COUNTER.
Likewise, the selected type commonly applies to the two comparators on the DIFFERENTIAL COUNTER.
You can differentiate the output type between the PULSE COUNTER and the DIFFERENTIAL COUNTER.
This circuit is turned on or off by the PULSE or DFL COUNTER INITIALIZE command
(initially, the latch is selected).
When the through-output of detection is selected, if you execute the COUNTER Command in the course of
the INT output, this output will be turned off for a duration of 50ns.
④: INT Output Enable Circuit
A signal that has passed through ① through ③ circuits above can be unconditionally confirmed from
the STATUS3 PORT.
This circuit is used for selecting whether this signal is to be externally output as
it is (XCNTINT or XDFLINT signal).
Output of the INT signal can be separately enabled or disabled for each of the pulse or DFL comparator.
This circuit is turned on or off by the PULSE or DFL COUNTER INITIALIZE command.
All setups except for the ① INT MASK circuit are done by the COUNTER INITIALIZE command.
Thus, these setups must be complete before pulse output it turned on.
Note: Unlike the INT output or STATUS, comparator's pulse output stop function is directly enabled without
going through the above mentioned circuit.
The following shows pages in this manual that bear descriptions relevant to this function:
The PULSE COUNTER INITIALIZE Command
page 33
The DFL COUNTER INITIALIZE Command
page 39
The INT MASK Command
page 51
Timing of each signal
page 75, 76
Summary of Contents for C-875
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