Display Netlist Information Functions

Some example functions that can be run to display information in a netlist:

1. print the hierarchy in a netlist

2. print each library with its definitions in a netlist

3. print connections between ports of each instance in a netlist

4. print the number of times each primitive is instanced

Note: because the hierarchy function uses recursion, the maximum recursion depth may be exceeded if used for large designs

For an even simpler display of netlist information, try using these functions with the Minimal Script example.

Also, JensRestemeier (not affiliated with BYU CCL) created a tool to generate images of netlists. See his github repository.

import spydrnet as sdn
from spydrnet.util.selection import Selection

#print the hierarchy of a netlist
def hierarchy(current_instance,indentation="",level=0):
    print(indentation,level,'',current_instance.name," --instance of",current_instance.reference.name,"--")
    for child in current_instance.reference.children:
        hierarchy(child,indentation+"     ",level+1)

#print a list of all libraries and definitions in a netlist
def libraries_definitions(my_netlist):
    for library in my_netlist.libraries:
        definitions = list(definition.name for definition in library.definitions)
        print("DEFINITIONS IN '",library.name,"':",definitions)

#prints each instance and it's connections (what inputs to it and what it outputs to)
def print_connections(current_netlist):
    print("CONNECTIONS:")
    for instance in current_netlist.get_instances():
        print("Instance name:",instance.name)
        for out_going_pin in instance.get_pins(selection = Selection.OUTSIDE,filter=lambda x: x.inner_pin.port.direction is sdn.OUT):
            if out_going_pin.wire:
                next_instances = list(str(pin2.inner_pin.port.name + ' of ' + pin2.instance.name) for pin2 in out_going_pin.wire.get_pins(selection = Selection.OUTSIDE, filter = lambda x: x is not out_going_pin))
                print('\t','Port',out_going_pin.inner_pin.port.name,'---->',next_instances)
        for in_coming_pin in instance.get_pins(selection = Selection.OUTSIDE,filter=lambda x: x.inner_pin.port.direction is sdn.IN):
            if in_coming_pin.wire:
                previous_instances = list(pin2 for pin2 in in_coming_pin.wire.get_pins(selection = Selection.OUTSIDE, filter = lambda x: x is not in_coming_pin))
                checked_previous_instances = list(str(x.inner_pin.port.name + ' of ' + x.instance.name) for x in previous_instances if (x.inner_pin.port.direction is sdn.OUT or (x.inner_pin.port.direction is sdn.IN and not x.instance.is_leaf()))is True)
                print('\t',checked_previous_instances,'---->','Port',in_coming_pin.inner_pin.port.name)

#print the number of times each primitive is instanced
def instance_count(current_netlist):
    print("Number of times each primitive is instanced:")
    primitives_library = next(current_netlist.get_libraries("hdi_primitives"),None)
    for primitive in primitives_library.get_definitions():
        count = 0
        for instance in current_netlist.get_instances():
            if primitive.name == instance.reference.name:
                count += 1
        print('\t',primitive.name,": ",count)



netlist = sdn.load_example_netlist_by_name("fourBitCounter")

print("HIERARCHY:")
hierarchy(netlist.top_instance)
libraries_definitions(netlist)
print_connections(netlist)
instance_count(netlist)