ANTENNADIFFAREA attribute problem

[ideal world]

Hi all,

I am using ic compiler in my design. But when I get the lefs from my design I found ANTENNADIFFAREA attribute in all the layer for all the pins in the design including the layers that I don't use.

I sourced the antenna rules from the library I use then I routed.

Actually, I don't know what this attribute means
I don't know how this happened and how can I put or remove this attribute during my design?

Any help (((

Thanks alot

 

[rca]

antenna diff area is used to indicate the antenna protection of this pin.

 

[vbommadeni]

ANTENNADIFFAREA value [LAYER layerName]
Specifies the diffusion (diode) area, in micron-squared units, to which the pin is connected on a layer.
If you do not specify a layer name, the value applies to all layers.

The above attribute has to be there in our standard cell lef file, when you are loading the design in IC Compiler.
If it is existed, but not mentioned the layerName then tool will applies to all layers and all the pins.

Here I am giving one example, how it has to be in standard cell lef file have the statements.
PIN Z
DIRECTION OUTPUT ;
USE SIGNAL ;
ANTENNADIFFAREA 0.0225 LAYER M2 ;
PORT
LAYER M2 ;
POLYGON 0.48 0.725 0.075 0.725 0.075 0.675 0.43 0.675 0.43 0.175 0.48 0.175 ;
END
END Z

does my comments helpful to you?

Thanks
Venkat

 

[ideal world]

So how can we add it to the design in icc so that it appears in the lef after that?

 

[vbommadeni]

define_io_antenna_area is the command in ICC to define ANTENNADIFFAREA.
you can search about the command usage.

I am giving an example on the command.
define_io_antenna_area -pin_name CLK_in -values { {metal1 100.5 true} {metal1 150 false} {metal2 200 true} {via1 10 false} {via2 20 false} }