get_fanins (::quartus::sdc_ext)

The following table displays information for the get_fanins Tcl command:

Tcl Package and Version

Belongs to ::quartus::sdc_ext 1.0

Syntax get_fanins [-h | -help] [-long_help] [-asynch] [-clock] [-inverting_paths] [-no_logic] [-non_inverting_paths] [-stop_at_clocks] [-synch] [-through <names> ]
Arguments -h | -help Short help
-long_help Long help with examples and possible return values
-asynch Traverse through asynch edges
-clock Traverse through clock edges
-inverting_paths Only follow inverting combinational paths
-no_logic Do not follow combinational paths
-non_inverting_paths Only follow non-inverting combinational paths
-stop_at_clocks Return clock targets as fanin/fanouts rather than traversing through them
-synch Traverse through synch edges
-through <names> Valid through nodes (string patterns are matched using Tcl string matching)
<filter> Valid starting nodes (string patterns are matched using Tcl string matching or collection)
Returns a collection of fanin ports, registers (and 
optionally clock targets) reachable from from the
<filter> in the design. When you supply the -no_logic
option, get_fanins ignores the paths that pass through
combinational logic elements other than buffers and

When you use the -synch, -asynch or -clock options,
get_fanins traverses the netlist through corresponding
edges. More than one of these options can be
specified. If you do not specify any of these three
options, the command does not ignore any paths.

When the -non_inverting_paths option is used, no_logic
does not follow any paths that includes odd number of
inverters. Similarly, when the -inverting_paths option
is used, no_logic does not follow any paths that
includes even number of inverters. Both the
-non_inverting_paths and -inverting_paths options
require the -no_logic option and are mutually

When the -through option is used, only the fanins that
can be reached by going through those nodes are

When -stop_at_clocks is used, combinational clock targets may 
be returned (in addition to clock or non-clock registers 
and ports), and registers or ports that can only be reached 
by traversing through a clock target will not be returned.

The filter for the collection is a Tcl list of
wildcards, and must follow standard Tcl or
TimeQuest-extension substitution rules.  See the help
for the use_timequest_style_escaping command for

Avoid using the get_fanins command if your design
targets a HardCopy series device or if you plan to
migrate your design to a HardCopy series device.
Example Usage
set fanins [get_fanins $item -synch -clock]
foreach_in_collection fanin_keeper $fanins {
	lappend fanin_keeper_list [get_node_info $fanin_keeper -name]

set fanins_no_logic [get_fanins $item -no_logic -asynch]
foreach_in_collection fanin_keeper $fanins_no_logic {
	lappend fanin_keeper_list_no_logic [get_node_info $fanin_keeper -name]

#-through example
get_fanins inst18 -through inst11
Return Value Code Name Code String Return
TCL_OK 0 INFO: Operation successful