NanDigits Design Automation

Automatic Functional ECO

Abstract

The use case shows how to automatically fix two logic failing points in the implementation netlist.

Netlist implementation.gv has two failing points compared to netlist reference.gv. The two failing points, "state_reg_0_/D" and "state_reg_1_/D", are added into the argument list of "fix_logic" command.

The "fix_logic" command analyzes and optimizes the logic cone in the implementation netlist by referencing to the logic cone in the reference netlist. A minimum number of gate patch is created and applied to the failing logic cone.

GofCall ECO Script

# GofCall ECO script, run_example.pl
use strict;  
undo_eco;  # Discard previous ECO operations
setup_eco("eco_example");  # Setup ECO name
read_library("art.90nm.lib"); # Read in standard library
read_design("-ref", "reference.gv");  # Read in the Reference Netlist
read_design("-imp", "implementation.gv");  # Read in the implementation Netlist Which is under ECO
set_top("topmod");  # Set the top module that ECO is working on
# die;  # User can uncomment out 'die' to let GOF stop here and do interactive debugs 

my @fixpoints; # Define the fix points 
push @fixpoints, "state_reg_0_/D"; # Fill in the failing point reported from LEC tool
push @fixpoints, "state_reg_1_/D";  # Fill in the failing point reported from LEC tool
fix_logic(@fixpoints);  # Execute fix_logic command to fix all the failing points

report_eco();  # ECO report
write_verilog("eco_verilog.v"); # Write out ECO result in Verilog
write_soce("eco_soce.tcl"); # Write out TCL script for SOC Encounter 

exit; # Exit when the ECO is done, comment it out to go to interactive mode when 'GOF >' appears

How to run the example

The example is in the released package. The steps to run the example:

• cd GOF/example
• run_example

The log file shows there are total 35 gates in the initial logic cone. After optimization, the patch has only 3 gates

Resource

Please read Use Cases for all use cases.

For other usages and flows, check Online Manual for more detail