Calculation of Power , Area

[noName456]

I'm currently trying to perform power and area analysis on Genus Synthesis Solution.
I have my 4 files including my top module, as
top.v , submod1.v submod2.v, submod3.v

On performing synthesis, the power and area calculated for top module is less than the sum of power and areas of the submodule.
Say top has power x nW, submodules all together have 5x nW.

Any solution to help resolve this?

 

[shlooky]

Hi there,

First we need to know what kind of power consumption we are talking about.
There is leakage (or static) power dependent on the cell size, or ultimately the transistor size. Dynamic power is dependent on switching (see the famous formula for dynamic power.... alpha*V^2*f). Internal power relates to switching inside the cell.

The values for dynamic and internal power provided by Genus and Innovus are usually garbage as these are strongly dependent on the input data waveforms. You have to give VCD file to the tools (or other format) to have correct answers. Otherwise, the tool will calculate an estimate based on its default switching settings.

For Sign-Off precision you need to run Voltus. You will need to create libraries with power data for Voltus first and after that you can analyze your design with specific VCDs...

Shlooky

 

[noName456]

Hi there,

First we need to know what kind of power consumption we are talking about.
There is leakage (or static) power dependent on the cell size, or ultimately the transistor size. Dynamic power is dependent on switching (see the famous formula for dynamic power.... alpha*V^2*f). Internal power relates to switching inside the cell.

The values for dynamic and internal power provided by Genus and Innovus are usually garbage as these are strongly dependent on the input data waveforms. You have to give VCD file to the tools (or other format) to have correct answers. Otherwise, the tool will calculate an estimate based on its default switching settings.

For Sign-Off precision you need to run Voltus. You will need to create libraries with power data for Voltus first and after that you can analyze your design with specific VCDs...

Shlooky

To be more precise with the problem I'm facing,
The power report that is generated for the top module, is supposed to show the power dissipation of each of the individual submodules in the design. But the generated report has only 1 of the 3 submodules, even though all the modules are instantiated inside the top module. Because of which, power dissipation is less than the sum of power dissipation of the submodules.
Thank you

 

[shlooky]

Hi,

what exactly is the command you are using? have you consulted "report_power -help" or "report_power -by_hierarchy -help" ?

Also,
isn't just Genus optimizing/changing the hierarchy during synthesis?
check your "ungrouping" setup. if you want to keep the original hierarchy, you need to run this prior synthesis:

"set_db / .auto_ungroup none"


Shlooky

 

[ThisIsNotSam]

Most likely genus is optimizing the hierarchy and creating confusion for you.