Unable to display the simulation with EDAPlayground compiler

Question

I have tried the following code from myHDL manual on EDAPlayground.com, but it didn't print anything out for me. Can anyone show me why ? and how to solve this ?

My configuration on the site is outlined here.

Testbench+Design : Python only Methodology : MyHDL 0.8

---

from random import randrange from myhdl import *

ACTIVE_LOW, INACTIVE_HIGH = 0, 1

def Inc(count, enable, clock, reset, n):

""" Incrementer with enable.

count -- output
enable -- control input, increment when 1
clock -- clock input
reset -- asynchronous reset input
n -- counter max value

"""

@always_seq(clock.posedge, reset=reset)
def incLogic():
    if enable:
        count.next = (count + 1) % n

return incLogic

def testbench():

count, enable, clock = [Signal(intbv(0)) for i in range(3)]

# Configure your reset signal here (active type, async/sync)
reset = ResetSignal(0,active=ACTIVE_LOW,async=True)



## DUT to be instantiated
inc_1 = Inc(count, enable, clock, reset, n=4)

HALF_PERIOD = delay(10)


## forever loop : clock generator

@always(HALF_PERIOD)
def clockGen():
    clock.next = not clock

## Stimulus generator
@instance
def stimulus():
    reset.next = ACTIVE_LOW
    yield clock.negedge
    reset.next = INACTIVE_HIGH
    for i in range(12):
        enable.next = min(1, randrange(3))
        yield clock.negedge
    raise StopSimulation

@instance
def monitor():
    print "enable  count"
    yield reset.posedge
    while 1:
        yield clock.posedge
        yield delay(1)
        print "   %s      %s" % (enable, count)

return clockGen, stimulus, inc_1, monitor


tb = testbench()

def main():
    Simulation(tb).run()

Answer 1

You need to call the main() function at the end. Eg, add a line

main()

at the end, or better, use Python's idiom of

if __name__=="__main__": 
     main()