def test_basic(self):
d = Node(State.low, name="D")
clk = Node(State.high, name="Clk")
ff = DTypeFlipFlop([d, clk])
ff.calculate()
assert ff.outputs["Q"].state == State.low
assert ff.outputs["QBar"].state == State.high
d.state = State.high
clk.state = State.high
ff.calculate()
assert ff.outputs["Q"].state == State.high
assert ff.outputs["QBar"].state == State.low
def test_no_change_state_high_output(self):
d = Node(State.high, name="D")
clk = Node(State.high, name="Clk")
ff = DTypeFlipFlop([d, clk])
ff.calculate()
assert ff.outputs["Q"].state == State.high
assert ff.outputs["QBar"].state == State.low
d.state = State.low
clk.state = State.low
ff.calculate()
assert ff.outputs["Q"].state == State.high
assert ff.outputs["QBar"].state == State.low
d.state = State.high
clk.state = State.low
ff.calculate()
assert ff.outputs["Q"].state == State.high
assert ff.outputs["QBar"].state == State.low
d.state = State.low
clk.state = State.low
ff.calculate()
assert ff.outputs["Q"].state == State.high
assert ff.outputs["QBar"].state == State.low
def test_last_state(self):
"""
Tests that Set=low & Reset=Low provides the previous state
"""
set_node = Node(State.low, name="Set")
reset_node = Node(State.high, name="Reset")
latch = SRNandLatch([set_node, reset_node])
out_nodes = latch.calculate()
assert out_nodes["Q"] == State.high
assert out_nodes["QBar"] == State.low
set_node.state = State.high
reset_node.state = State.high
out_nodes = latch.calculate()
assert out_nodes["Q"] == State.high
assert out_nodes["QBar"] == State.low
set_node.state = State.high
reset_node.state = State.low
out_nodes = latch.calculate()
assert out_nodes["Q"] == State.low
assert out_nodes["QBar"] == State.high
set_node.state = State.high
reset_node.state = State.high
out_nodes = latch.calculate()
assert out_nodes["Q"] == State.low
assert out_nodes["QBar"] == State.high