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> ] <filter>
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 the
<filter> in the design. When you supply the -no_logic
option, get_fanins ignores paths that pass through
combinational logic elements other than buffers and

NOTE: the -no_logic option does not consider
logic absorbed into the cells of the <filter> nor the
cells of fanin registers, ports or clock targets.

When you use -synch, -asynch, or -clock options,
get_fanins traverses the netlist through corresponding
edges. You can specify more than one of these options.
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
Timing Analyzer-extension substitution rules.  See the help
for the use_timing_analyzer_style_escaping command for
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