Altera Quartus II Scripting - Manual (Page 605)

Chapter 3: Tcl Packages & Commands 3–475
timing
© July 2013 Altera Corporation Quartus II Scripting Reference Manual
compute_slack_on_edges
Usage
compute_slack_on_edges [-min]
Options
-min: Option to compute minimum slack
Description
Computes slack on all edges between non-combinational nodes.
This command computes slack on every edge in all constrained data paths.The algorithm used to compute
slack is the same as that used by the Fitter.
Example
load_package advanced_timing
set max_slack "2147483.647"
project_open chiptrip
create_timing_netlist -skip_dat
# Perform timing analysis on the design
# and compute slack on every edge that is part
# of a constrained path
compute_slack_on_edges
# Iterate through all edges to display any edge with negative slack
set fail_count 0
set no_constraint_count 0
set ok_count 0
foreach_in_collection edge [get_timing_edges] {
set slack [lindex [get_timing_edge_info -info slack $edge] 0]
if { $slack < $max_slack } {
if { $slack < 0 } {
puts "$edge : Slack = $slack"
incr fail_count
} else {
incr ok_count
}
} else {
incr no_constraint_count
}
}
puts "Edges meeting timing: $ok_count"
puts "Edges failing timing: $fail_count"
puts "Edges without constraints: $no_constraint_count"
delete_timing_netlist
project_close