Altera Quartus II Scripting - Manual (Page 420)

3–290 Chapter 3: Tcl Packages & Commands
sdc
Quartus II Scripting Reference Manual © July 2013 Altera Corporation
derive_clocks
Usage
derive_clocks -period <period_value> [-waveform <edge_list>]
Options
-period <period_value>: Speed of the default clock in terms of clock period
-waveform <edge_list>: List of edge values
Description
Creates a clock on sources of clock pins in the design that do not already have at least one clock sourcing
the clock pin. This command is equivalent to calling create_clock on each clock source in the design that
does not already have a clock assigned to it.
See the help for create_clock for more information.
Altera does not recommend using this command during final sign-off analysis of a design. derive_clocks
should only be used early in the design phase when the clocks are not completely known. When possible,
create_clock and create_generated_clock should be used instead.
Example
# Automatically create a 10ns, 60% duty cycle clock on all
# unconstrained clock sources
derive_clocks -period 10 -waveform {0 6}