def _resolve(self, expr):
sim = Simulator(Module())
a = []
def testbench():
a.append((yield expr))
sim.add_process(testbench)
sim.run()
return a[0]
def testbench():
from nmigen.sim.pysim import Settle, Simulator
unit = NotGate()
def bench():
yield unit.input.eq(0)
yield Settle()
assert (yield unit.output)
yield unit.input.eq(1)
yield Settle()
assert not (yield unit.output)
sim = Simulator(unit)
sim.add_process(bench)
with sim.write_vcd("notgate.vcd",
"notgate.gtkw",
traces=[unit.input, unit.output]):
sim.run()
def elaborate(self, platform):
m = Module()
m.submodules += [
self.timing,
self.still,
]
return m
if __name__ == '__main__':
color_depth = 4
image = gradient(color_depth=color_depth)
timing = VgaTiming(resolutions[ResolutionName.VGA_640_480p_60hz])
dut = TestBench(
timing,
Still(timing, color_depth=color_depth, image=image),
)
sim = Simulator(dut)
def proc():
for _ in range(800 * 40):
yield
sim.add_clock(1e-6, domain='pixel')
sim.add_sync_process(proc, domain='pixel')
with sim.write_vcd('still.vcd'):
sim.run()
class LunaGatewareTestCase(unittest.TestCase):
domain = 'sync'
# Convenience property: if set, instantiate_dut will automatically create
# the relevant fragment with FRAGMENT_ARGUMENTS.
FRAGMENT_UNDER_TEST = None
FRAGMENT_ARGUMENTS = {}
# Convenience properties: if not None, a clock with the relevant frequency
# will automatically be added.
FAST_CLOCK_FREQUENCY = None
SYNC_CLOCK_FREQUENCY = 120e6
USB_CLOCK_FREQUENCY = None
def instantiate_dut(self):
""" Basic-most function to instantiate a device-under-test.
By default, instantiates FRAGMENT_UNDER_TEST.
"""
return self.FRAGMENT_UNDER_TEST(**self.FRAGMENT_ARGUMENTS)
def get_vcd_name(self):
""" Return the name to use for any VCDs generated by this class. """
return "test_{}".format(self.__class__.__name__)
def setUp(self):
self.dut = self.instantiate_dut()
self.sim = Simulator(self.dut)
if self.USB_CLOCK_FREQUENCY:
self.sim.add_clock(1 / self.USB_CLOCK_FREQUENCY, domain="usb")
if self.SYNC_CLOCK_FREQUENCY:
self.sim.add_clock(1 / self.SYNC_CLOCK_FREQUENCY, domain="sync")
if self.FAST_CLOCK_FREQUENCY:
self.sim.add_clock(1 / self.FAST_CLOCK_FREQUENCY, domain="fast")
def initialize_signals(self):
""" Provide an opportunity for the test apparatus to initialize siganls. """
yield Signal()
def traces_of_interest(self):
""" Returns an interable of traces to include in any generated output. """
# Default to including all signals.
return self.sim._signal_names
def simulate(self, *, vcd_suffix=None):
""" Runs our core simulation. """
# If we're generating VCDs, run the test under a VCD writer.
if os.getenv('GENERATE_VCDS', default=False):
# Figure out the name of our VCD files...
vcd_name = self.get_vcd_name()
if vcd_suffix:
vcd_name = "{}_{}".format(vcd_name, vcd_suffix)
# ... and run the simulation while writing them.
traces = self.traces_of_interest()
with self.sim.write_vcd(vcd_name + ".vcd",
vcd_name + ".gtkw",
traces=traces):
self.sim.run()
else:
self.sim.run()
@staticmethod
def pulse(signal, *, step_after=True):
""" Helper method that asserts a signal for a cycle. """
yield signal.eq(1)
yield
yield signal.eq(0)
if step_after:
yield
@staticmethod
def advance_cycles(cycles):
""" Helper methods that waits for a given number of cycles. """
for _ in range(cycles):
yield
@staticmethod
def wait_until(strobe, *, timeout=None):
""" Helper method that advances time until a strobe signal becomes true. """
cycles_passed = 0
while not (yield strobe):
yield
cycles_passed += 1
if timeout and cycles_passed > timeout:
raise RuntimeError(
f"Timeout waiting for '{strobe.name}' to go high!")
def _ensure_clocks_present(self):
""" Function that validates that a clock is present for our simulation domain. """
frequencies = {
'sync': self.SYNC_CLOCK_FREQUENCY,
'usb': self.USB_CLOCK_FREQUENCY,
'fast': self.FAST_CLOCK_FREQUENCY,
}
self.assertIsNotNone(
frequencies[self.domain],
f"no frequency provied for `{self.domain}`-domain clock!")
def wait(self, time):
""" Helper method that waits for a given number of seconds in a *_test_case. """
# Figure out the period of the clock we want to work with...
if self.domain == 'sync':
period = 1 / self.SYNC_CLOCK_FREQUENCY
elif self.domain == 'usb':
period = 1 / self.USB_CLOCK_FREQUENCY
elif self.domain == 'fast':
period = 1 / self.FAST_CLOCK_FREQUENCY
# ... and, accordingly, how many cycles we want to delay.
cycles = math.ceil(time / period)
print(cycles)
# Finally, wait that many cycles.
yield from self.advance_cycles(cycles)
def test_sim_noiseshaper(self):
fmt = Q(8, 18)
input = fmt.Signal()
dut = Noiseshaper(input, order=8, n_lev=64)
sim = Simulator(dut)
sim.add_clock(1 / 100e6)
input_hist = []
output_hist = []
integrators_hist = [[] for _ in dut.stages]
n = 8192
f_nyquist = int(np.ceil(n / (2. * dut.osr)))
f_test = np.floor(2. / 3. * f_nyquist)
u = dut.n_lev * 0.5 * np.sin(2 * np.pi * f_test / n * np.arange(n))
def testbench():
for x in u:
yield input.eq(x)
input_hist.append(fmt.to_float((yield input.value)))
output_hist.append(
fmt.to_float((yield dut.quantized_value.value)))
for i, integrator in enumerate(dut.stages):
integrators_hist[i].append(
fmt.to_float((yield integrator.value)))
yield
sim.add_sync_process(testbench)
sim.run()
from matplotlib import pyplot as plt
plt.plot(np.arange(n), output_hist, linewidth=1, label="output")
plt.plot(np.arange(n), input_hist, label="input")
plt.legend()
plt.show()
for i, integrator_hist in reversed(list(enumerate(integrators_hist))):
plt.plot(np.arange(n),
integrator_hist,
linewidth=1,
label="integrator {}".format(i))
plt.legend()
plt.show()
import deltasigma as ds
f = np.linspace(0, 0.5, int(n / 2. + 1))
v, xn, xmax, y = ds.simulateDSM(u,
dut.h,
nlev=len(dut.quantization_values))
spec = np.fft.fft(v * ds.ds_hann(n)) / (n / 4)
plt.plot(f, ds.dbv(spec[:int(n / 2. + 1)]), 'b', label='Simulation DS')
spec = np.fft.fft(output_hist * ds.ds_hann(n)) / (n / 4)
plt.plot(f,
ds.dbv(spec[:int(n / 2. + 1)]),
'g',
label='Simulation HW',
alpha=0.7)
ds.figureMagic([0, 0.5], 0.05, None, [-160, 0], 20, None, (16, 6),
'Output Spectrum')
plt.xlabel('Normalized Frequency')
plt.ylabel('dBFS')
snr = ds.calculateSNR(spec[2:f_nyquist + 1], f_test - 2)
plt.text(0.05,
-10,
'SNR = %4.1fdB @ OSR = %d' % (snr, dut.osr),
verticalalignment='center')
NBW = 1.5 / n
Sqq = 4 * ds.evalTF(dut.h, np.exp(2j * np.pi * f))**2 / 3.
plt.plot(f, ds.dbp(Sqq * NBW), 'm', linewidth=2, label='Expected PSD')
plt.text(0.49,
-90,
'NBW = %4.1E x $f_s$' % NBW,
horizontalalignment='right')
plt.legend(loc=4)
plt.show()
pwm_out = py_pwm.modulate(np.array(output_hist) + 32,
n_bits=6,
oversampling_ratio=1)
n = n * 64
f = np.linspace(0, 0.5, int(n / 2. + 1))
spec = np.fft.fft(pwm_out * ds.ds_hann(n)) / (n / 4)
plt.plot(f, ds.dbv(spec[:int(n / 2. + 1)]), 'b', label='PWM')
ds.figureMagic([0, 0.5], 0.05, None, [-160, 0], 20, None, (16, 6),
'Output Spectrum')
plt.xlabel('Normalized Frequency')
plt.ylabel('dBFS')
snr = ds.calculateSNR(spec[2:f_nyquist + 1], f_test - 2)
plt.text(0.05,
-10,
'SNR = %4.1fdB @ OSR = %d' % (snr, dut.osr),
verticalalignment='center')
plt.legend(loc=4)
plt.show()