const.py

from nmigen import *
from nmigen.lib.io import *
from nmigen.back.pysim import *
from nmigen.cli import main
from nmigen.asserts import Rose, Fell
from cic_bus import CICBus
import random

region_id = Const(0b0001) # NTSC, make configurable later

# CIC control module
class CICTop(Elaboratable):
    def __init__(self):
        pass

    def ports(self):
        pass

    def elaborate(self, platform):
        m = Module()
        
        bus_input = Signal()
        counter = Signal(range(region_id.width))

        # state machine
        with m.FSM() as fsm:
            """
            REGION ID STATE:
            write the 4 bits of the Region ID
            """
            with m.State("REGION_ID"):
                m.d.sync += bus_input.eq(region_id[counter])
                m.d.sync += counter.eq(counter + 1 )

        return m