open_saif - 2022.1 English

Vivado Design Suite Tcl Command Reference Guide (UG835)

Document ID
Release Date
2022.1 English

Open file for storing signal switching rate for power estimation. The switching rate is written out in Switching Activity Interchange Format (SAIF) Only one SAIF is allowed to be open per simulation run.


open_saif [‑quiet] [‑verbose] <file_name>


The SAIF object that was opened.


Name Description
[-quiet] Ignore command errors
[-verbose] Suspend message limits during command execution
<file_name> The SAIF filename to store information



Create or open a Switching Activity Interchange Format (SAIF) file for storing signal switching rates in the current simulation for later use by the report_power command.

The Switching Activity Interchange format (SAIF) file is an ASCII file containing header information, and toggle counts for the specified signals of the design. It also contains the timing attributes which specify time durations for signals at level 0, 1, X, or Z.

The SAIF file is recommended for power analysis since it is smaller than the VCD file.

When an SAIF file has been opened, you can write the switching activity from the simulation into the SAIF file using log_saif.

Only one SAIF can be open at one time during simulation. To close the SAIF file, use the close_saif command.

This command returns the object ID of the opened SAIF file, or returns an error if the command failed.


-quiet - Execute the command quietly, ignore any command line errors, and return no error messages if the command fails to execute.

-verbose - Suspends message limits during command execution.

<file_name> - Specifies the name of the SAIF file to open.


The following example opens the specified simulation:

open_saif myData.saif