Altera SDC and TimeQuest API - Manual (Page 48)

2–38 Chapter 2: SDC and TimeQuest API Package and Commands
sdc
SDC and TimeQuest API Reference Manual © December 2009 Altera Corporation
The -rise_from and -fall_from options can be used in place of the destination nodes specified using the
-from option. The rise or fall value of the option indicates that the "from" nodes are driven by the rising or
falling edge of the clock that feeds this node taking into consideration any logical inversions along the
clock path. The -from option is the combination of both rising and falling "from" nodes. If the -from
collection is a clock collection, the assignment applies to those nodes that are driven by the respective
rising or falling clock edge.
The -rise_to and -fall_to options behave similarly to the "from" options described previously. These
assignments restrict the given assignment to only those nodes or clocks that correspond to the specified
rise or fall value taking into consideration any logical inversions that are along the clock path.
The values of the -from, -to, -through, and other similar options are either collections or a Tcl list of
wildcards used to create collections of appropriate types. The values used must follow standard Tcl or
TimeQuest-extension substitution rules. See help for the use_timequest_style_escaping command for
details.
Example
# Apply a 0ns min delay between two unrelated clocks
set_min_delay -from [get_clocks clkA] -to [get_clocks clkB] 0.000
# Apply a 0ns min delay for an input port (TH)
set_min_delay -from [get_ports in[*]] -to [get_registers *] -.000
# Apply a 0.5ns min delay for an output port (MIN_TCO)
set_min_delay -from [get_registers *] -to [get_ports out[*]] 0.500
# Apply a 0.5ns min delay for an input port to an output port (MIN_TPD)
set_min_delay -from [get_ports in[*]] -to [get_ports out[*]] 0.500
# Apply a 0.5ns min delay for an input port only to nodes driven by
# the falling edge of clock CLK
set_max_delay -from [get_ports in[*]] -fall_to [get_clocks CLK] 0.500