log_saif - 2022.1 English

Vivado Design Suite Tcl Command Reference Guide (UG835)

Document ID
Release Date
2022.1 English

Log Switching Activity Interchange Format (SAIF) toggle for specified wire, signal, or reg


log_saif [‑quiet] [‑verbose] <hdl_objects>...


Does not return any object.


Name Description
[-quiet] Ignore command errors
[-verbose] Suspend message limits during command execution
<hdl_objects> The hdl_objects to log



Writes the switching activity rates for the specified HDL signals during the current simulation.

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 log_saif command can only be used after the open_saif command has opened an SAIF file in the current simulation to capture switching activity rates.


-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.
Note: Any errors encountered on the command-line, while launching the command, will be returned. Only errors occurring inside the command will be trapped.
-verbose - (Optional) Temporarily override any message limits and return all messages from this command.
Note: Message limits can be defined with the set_msg_config command.

<hdl_objects> - Specifies the HDL signal names on which to capture code.


The following example logs switching activity for all signals in the current_scope:
log_saif [ get_objects ]
Log SAIF for only the internal signals starting with name c of the scope /tb/UUT:
log_saif [get_objects -filter { type == internal_signal }/tb/UUT/c*]