Setting Constraints in tcl file for cone

[sarfaraz.ahmed]

Hi,

can anyone help how to set Constraints of fanin and then save that cone ? actually, I traverse back from my output to input and I want to list all gates comes under that output cone ?
Is there any setting in tcl file then please share here. I below show the tcl file which i write but I think something is missing for making the proper cone.

## Define the search path
set_attribute lib_search_path /home/sarfaraz.ahmed/techlib/FreePDK45/osu_soc/lib/source/signalstorm/files/
 
 
## This defines the library to use
set_attribute library gscl45nm.lib
 
## Read in verilog cod
read_hdl /home/sarfaraz.ahmed/RC/top.v

# This command to exclude the cell
set_attribute avoid true FAX1 XOR* OR* XNOR* NOR* HAX1 OAI* AOI* AND* BUF* MUX* 
 
#set_attribute preserve true NAND2X1

## This creates a technology-independent schematic
elaborate
 
 
##set_attribute avoid true
## Create a technology-dependent schematic
synthesize -to_mapped
 
## Write out synthesized verilog netlist
write -mapped > top_synth.v
 
## Write out the SDC file we will take into the place n route tool
write_sdc > ./encounter/top_synth.sdc

## setting constraints for cone of n_1 output
dc::all_fanin -to n_1

Thanking in the anticipation

 

[ThisIsNotSam]

a) your sample script is not setting any constraint other then some dont_use cells
b) I don't understand what you are trying to do. you want a list of timing paths? how is this related to fanins or fanouts? why don't you list paths using report_timing -from xxx -to xxx???

 

[sarfaraz.ahmed]

Thanks.

Actually I want to see all instance which are fanin of my 1st output let say. It gives the result by the command :

rc:/> dc::all_fanin -to g118/B -only_cells

when this command run on terminal It lists all instances for example in that case it gives:

"/designs/FA/instances_comb/g118 /designs/FA/instances_comb/g124 /designs/FA/instances_comb/g119 /designs/FA/instances_comb/g121 /designs/FA/instances_comb/g127 /designs/FA/instances_comb/g125

this result is fine with me but now two things which I want to ask:

1- When I write this command in tcl script it does not shows the result in terminal window and also don't make instances log, but when i run this command on rc prompt it shows above result (list of all instances). So How I get its log where I can see these all instance ? because I want to save these instances to use in another MATLAB script. But I couldn't find a way to save or log these instances


2- If I want to make its a part of my tcl script how can I see all the instances in log as well as on terminal window ?

see an attachment please.

Thank you

 

[sarfaraz.ahmed]

Even, I used redirect commands on rc prompt but its create only empty file. It does not copy the instance on file. Please look into attachment.


how would I save these cells in a file ? even it creates "gates.rep" but only empty.

Thanks

 

[ThisIsNotSam]

save the content into a TCL list, then echo that list to a file using the redirection operator >>

should work