Create histogram
Syntax
create_slack_histogram [‑to <args>] [‑delay_type <arg>] [‑num_bins <arg>]
[‑max_paths <arg>] [‑slack_less_than <arg>] [‑slack_greater_than <arg>]
[‑group <args>] [‑significant_digits <arg>] [‑scale <arg>]
[‑file <arg>] [‑append] [‑details] [‑no_header] [‑name <arg>]
[‑cells <args>] [‑quiet] [‑verbose]Usage
| Name | Description |
|---|---|
[-to]
|
To clock |
[-delay_type]
|
Type of path delay: Values: max, min, min_max Default: max |
[-num_bins]
|
Maximum number of bins: Valid Range (1-100) Default: 10 |
[-max_paths]
|
Number of paths to consider for -timing option Default: INT_MAX |
[-slack_less_than]
|
Display paths with slack less than this Default: 1e+30 |
[-slack_greater_than]
|
Display paths with slack greater than this Default: -1e+30 |
[-group]
|
Limit report to paths in this group(s) |
[-significant_digits]
|
Number of digits to display: Range: 0 to 3 Default: 3 |
[-scale]
|
Type of scale on which to draw the histogram; Values: linear, logarithmic Default: linear |
[-file]
|
Filename to output results to. (send output to console if -file is not used) |
[-append]
|
Append the results to file, don't overwrite the results file |
[-details]
|
Report will generate detailed table |
[-no_header]
|
do not generate a report header |
[-name]
|
Output the results to GUI panel with this name |
[-cells]
|
run create_slack_histogram on the specified cell(s) |
[-quiet]
|
Ignore command errors |
[-verbose]
|
Suspend message limits during command execution |
Description
Create a slack histogram grouping paths into slack ranges, and displaying the results graphically or in text format.
Inside the text report, this command generates some slack tables based on the timing corners and number of paths that are analyzed. An optional detailed table provides specific information for all the analyzed endpoints.
In GUI report, this command creates a slack histogram grouping paths into slack ranges, and displaying the results graphically.
Arguments
-to <args> - (Optional) Specify a clock name, to analyze paths that end in the specified clock domain.
-delay_type <arg> - (Optional) Specifies the type of path delay to analyze when creating the slack report. The valid values are min, max, and min_max. The default setting for -delay_type is max.
-num_bins <args> - (Optional) Specify the number of slack bins to divide the results into. The number of bins determines the granularity of the histogram returned. The range of slack values calculated is divided evenly into the specified number of bins, and the paths are grouped into the bins according to their slack values. The value can be specified as a number between 1 and 100, with a default value of 10.
-max_paths <arg> - (Optional) The maximum number of paths to analyze. This is specified as a value greater than or equal to 1. By default the create_slack_histogram command will report all existing critical paths.
-slack_less_than <arg> - (Optional) Report slack on paths with a calculated slack value less than the specified value. Can be used with -slack_greater_than to provide a range of slack values of specific interest.
-slack_greater_than <arg> - (Optional) Report slack on paths with a calculated slack value greater than the specified value. Can be used with -slack_less_than to provide a range of slack values of specific interest.
-group <args> - (Optional) Report slack for paths in the specified path groups. Currently defined path groups can be determined with the get_path_groups command.
-significant_digits <arg> - (Optional) The number of significant digits in the output results. The valid range is 0 to 3. The default setting is 3 significant digits.
-scale [ linear | logarithmic ] - (Optional) Specify the Y-axis scale to use when presenting the slack histogram. Logarithmic allows for a smoother presentation of greatly different values, but linear is the default.
-scale is specific to the GUI report.
-details - (Optional) Provide a detailed table of the timing paths that are analyzed. The table lists each endpoint pin or port with the source/destination clock, and timing corner used for analysis.
-no_header - (Optional) Do not write a header to the report.
-file <arg> - (Optional) Write the report into the specified file. The specified file will be overwritten if one already exists, unless -append is also specified.
-append - (Optional) Append the output of the command to the specified file rather than overwriting it.
-append option can only be used with the -file option.
-name <arg> - (Optional) Specifies the name of the results set for the GUI. If the name specified is currently opened, the create_slack_histogram will overwrite the current results.
-cells <arg> - (Option) Generate the report for the specified hierarchical cells. The details of the report will be based on the specified cells rather than the whole design or current_instance.
-quiet - (Optional) Execute the command quietly, returning no messages from the command. The command also returns TCL_OK regardless of any errors encountered during execution.
-verbose - (Optional) Temporarily override any message limits and return all messages from this command.
set_msg_config command.Examples
Create a slack histogram of the current design, using the default values and outputting the results to the named result set in the GUI.
create_slack_histogram -name slack1Generate a slack histogram text report (including detailed table) of the current design, using the default values and outputting the results to the specified file.
create_slack_histogram -details -file text_report.txt