Intel® Quartus® Prime Pro Edition User Guide: Scripting

ID 683432
Date 9/26/2022
Public

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4.1.5.3. dni::create_clock (::quartus::dcmd_sdc)

The following table displays information for the dni::create_clock Tcl command:

Tcl Package and Version

Belongs to ::quartus::dcmd_sdc

Syntax dni::create_clock [-h | -help] [-long_help] [-add] [-comment <comment> ] [-name <name> ] -period <period> [-waveform <waveform> ] [ <source_objects> ]
Arguments -h | -help Short help
-long_help Long help with examples and possible return values
-add whether to add
-comment <comment> comment for creating a clock
-name <name> name for creating a clock
-period <period> period for creating a clock
-waveform <waveform> waveform for creating a clock
<source_objects> source objects for creating a clock
Description
Defines a clock. If the -name option is not used, the clock name is
the same as the first target in the list or collection. The clock name
is used to refer to the clock in other commands.

The -period option specifies the clock period. It is also possible to
use this option to specify a frequency to define the clock period.
This can be done by using -period option followed by either
<frequency>MHz or "<frequency> MHz". Please note this is a convenience
extension and using it is non-standard SDC syntax.

The -waveform option specifies the rising and falling edges (duty
cycle) of the clock, and is specified as a list of two time values:
the first rising edge and the next falling edge. The rising edge must
be within the range [0, period]. The falling edge must be within one
clock period of the rising edge. The waveform defaults to (0,
period/2).

If a clock with the same name is already assigned to a given target,
the create_clock command will return an error. If a clock with a
different name exists on the given target, the create_clock command
will be ignored unless the -add option is used. The -add option can be
used to assign multiple clocks to a pin or port.

If the target of the clock is internal (i.e. not an input port), the
source latency is zero by default.

If a clock is on a path after another clock, then it blocks or
overwrites the previous clock from that point forward.

The value of the targets is either a collection or a Tcl list of
wildcards used to create a collection of the appropriate type. The
values used must follow standard Tcl substitution rules.
Example Usage
dni::create_clock $period
Return Value Code Name Code String Return
TCL_OK 0 INFO: Operation successful