"""
An example usage of the circuit_sim library. We describe an XOR function using
a simple sum-of-products.
"""
from circuit_sim import Circuit
circuit = Circuit()
# Two inputs which go through all possible combinations of 0 and 1.
a = circuit.Stimulus({0: 0,
10: 1,
20: 0,
30: 1})
b = circuit.Stimulus({0: 0,
20: 1})
# Define XOR as a sum-of-products
neg_a = circuit.Inv(a.output)
neg_b = circuit.Inv(b.output)
just_a = circuit.And(a.output, neg_b.output)
just_b = circuit.And(neg_a.output, b.output)
a_xor_b = circuit.Or(just_a.output, just_b.output)
output = circuit.Probe(a_xor_b.output)
# Simulate the circuit for 40 time steps
import sys
circuit.simulate(sys.argv[1], 40)
def test_circuit_simulate(monkeypatch):
mock_mc = Mock()
class CtxtMgr(object):
def __enter__(self):
pass
def __exit__(self, type, value, traceback):
pass
mock_mc.application.side_effect = CtxtMgr
mock_mc.get_system_info.return_value = SystemInfo(1, 1, {
(0, 0): ChipInfo(num_cores=18,
core_states=[AppState.run] + [AppState.idle]*17,
working_links=set(Links),
largest_free_sdram_block=110*1024*1024,
largest_free_sram_block=1024*1024)
})
mock_filelike = Mock()
mock_mc.sdram_alloc_as_filelike.return_value = mock_filelike
mock_mc_constructor = Mock(return_value=mock_mc)
monkeypatch.setattr(circuit_sim, "MachineController", mock_mc_constructor)
# A simple ring oscillator
c = Circuit()
osc = c.Inv()
osc.input = osc.output
c.simulate("test-machine", 64)
# The simulation time tick attribute should be set up.
assert c.ticks == list(range(64))
# Correct hostname should have been used
mock_mc_constructor.assert_called_once_with("test-machine")
# Should have used context manager
mock_mc.application.assert_called_once_with()
# Should have fetched the machine
mock_mc.get_system_info.assert_called_once_with()
# Should have allocated SDRAM for the one and only device on chip (0, 0),
# the only one, and on core 1.
mock_mc.sdram_alloc_as_filelike.assert_called_once_with(
osc.sdram_required(64), 1, buffer_size=0, clear=False, x=0, y=0)
# Should have loaded only one application
mock_mc.load_application.assert_called_once_with({
osc.app_name: {(0, 0): set([1])}})
# Should have written the config accordingly
mock_filelike.write.assert_called_once_with(
b"\x40\x00\x00\x00"
b"\x00\x00\x00\x00"
b"\x00\x00\x00\x00")
# Should have loaded the routing tables
assert mock_mc.load_routing_tables.called
# Should have waited first for sync0 then exit
mock_mc.wait_for_cores_to_reach_state.assert_has_calls([
call("sync0", 1),
call("exit", 1),
])
# Should have sent a sync0 signal.
mock_mc.send_signal.assert_called_once_with("sync0")
