Create_base_clock, Usage, Options – Altera Quartus II Scripting User Manual
Page 615: Description, Create_base_clock –485
Chapter 3: Tcl Packages & Commands
3–485
timing_assignment
© July 2013
Altera Corporation
Quartus II Scripting Reference Manual
create_base_clock
Usage
create_base_clock [-comment <comment>] [-disable] [-duty_cycle <integer>] [-entity
<entity>] -fmax <fmax> [-no_target] [-tag <data>] [-target <name>] [-virtual]
<clock_name>
Options
-comment <comment>: Comment
-disable: Option to disable assignment
-duty_cycle <integer>: Duty cycle
-entity <entity>: Entity to which to add clock assignment
-fmax <fmax>: Clock frequency
-no_target: Option to not assign clock to node
-tag <data>: Option to tag data to this assignment
-target <name>: Clock node name
-virtual: Option to specify the clock as a virtual clock
<clock_name>: Clock name
Description
Creates the base clock. The base clock is an absolute clock.
The "-fmax" option can take the format:
<floating point time value><time unit>
For example, if the fmax is 10.55ns, "10.55" is the <floating point time value> and "ns" is the <time unit>.
The following table displays possible time units:
If you specify the "-virtual" option, the base clock is not assigned to any node in the timing netlist. You
cannot specify the "-virtual" option and the "-target" option at the same time.
For entity-specific assignments, use the "-entity" option to force the assignment to specified entity. If you
do not specify the "-entity" option, the value for the FOCUS_ENTITY_NAME assignment is used. If the
FOCUS_ENTITY_NAME value is not found, the revision name is used.
Time Unit
Description
s
second(s)
ms
millisecond(s)
us
microsecond(s)
ns
nanosecond(s)
ps
picosecond(s)
fs
femtosecond(s)
Hz
hertz
KHz
kilohertz
MHz
megahertz
GHz
gigahertz