We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome,
Internet Explorer 11,
Safari. Thank you!
AR# 63020: Vivado Power Analysis - How do I set switching activities for primary inputs (use set_switching_activity and set_input_delay command on specific protocol or handshaking inputs and data ports)?
Vivado Power Analysis - How do I set switching activities for primary inputs (use set_switching_activity and set_input_delay command on specific protocol or handshaking inputs and data ports)?
How do I set switching activities for primary inputs.
I am using the "set_switching_activity" and "set_input_delay" command on specific protocol or handshaking inputs and data ports.
The primary inputs should be constrained with a set_input_delay command.
In addition to the set_input_delay, the design specific handshaking (protocols, memory interface, etc) and data ports also need attention.
The activity rates on primary ports influences the dynamic power Report_power uses a default switching activity on all inputs (except clock and control ports), which means they will not match the real behavior of the hardware interface.
The default switching activity works fine on the majority of data ports.
But it will have a huge accuracy impact when it is applied to handshaking ports.
You will need to set the correct switching activity settings on these primary inputs.
The default activity settings can be changed in the Report_power GUI Settings Window or through Tcl Command:
Please note that it applies the same activity rate to all the primary inputs - it does not understand and distinguish handshaking ports from data ports.
So it is important to specify the activity rates manually to the hand-shaking ports.
This can be done either through a GUI or Tcl command.
***RECOMMENDATION*** Ensure correct switching info on primary I/O Ports.
results also identifies such primary ports in the design, so that you
can quickly validate the switching information on those nets and take the
It also gives the number of logic cells that are
affected by these nets - Fanout and Logic Type.
switching activity estimation does not seem correct, you can simply
select the 'net' in the Power view and edit the Power property in the 'Net
Properties' window or through the Tcl command below: