myhdl/example/cookbook/johnson/test_jc2.py

from myhdl import *

ACTIVE, INACTIVE = bool(0), bool(1)

from jc2 import jc2
from jc2_alt import jc2_alt

def convert(jc2):
    goLeft, goRight, stop, clk = [Signal(INACTIVE) for i in range(4)]
    q = Signal(intbv(0)[4:])
    toVerilog(jc2, goLeft, goRight, stop, clk, q)

convert(jc2)
convert(jc2_alt)


def test(jc2):
    
    goLeft, goRight, stop, clk = [Signal(INACTIVE) for i in range(4)]
    q = Signal(intbv(0)[4:])
    
    @always(delay(10))
    def clkgen():
        clk.next = not clk

    jc2_inst = jc2(goLeft, goRight, stop, clk, q)

    @instance
    def stimulus():
        for i in range(3):
            yield clk.negedge
        for sig, nrcycles in ((goLeft, 10), (stop, 3), (goRight, 10)):
            sig.next = ACTIVE
            yield clk.negedge
            sig.next = INACTIVE
            for i in range(nrcycles-1):
                yield clk.negedge
        raise StopSimulation

    @instance
    def monitor():
        print "goLeft goRight stop clk q"
        print "-------------------------"
        while True:
            yield clk.negedge
            yield delay(1)
            print "%d %d %d" % (goLeft, goRight, stop) ,
            yield clk.posedge
            print "C",
            yield delay(1)
            print bin(q, 4)

    return clkgen, jc2_inst, stimulus, monitor

sim = Simulation(test(jc2))
sim.run()

print
print "Alternative design"
print "------------------"
sim = Simulation(test(jc2_alt))
sim.run()