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gw: minor tweaks to peak detector to improve behaviour

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This commit is contained in:
David Lenfesty 2023-05-27 10:36:00 -06:00
parent 1d8c9ca224
commit 0185d81d46
1 changed files with 33 additions and 30 deletions
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63
gateware/sampler/peak_detector.py
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@ -36,12 +36,12 @@ class PeakDetector(Module):
""" """
def __init__(self, data_width: int): def __init__(self, data_width: int):
# Create all state signals # Create all state signals (underscored in self to be accessible in tests)
min_val = Signal(data_width) self._min_val = Signal(data_width)
max_val = Signal(data_width) self._max_val = Signal(data_width)
diff = Signal(data_width) self._diff = Signal(data_width)
triggered_time = Signal(32) self._triggered_time = Signal(32)
decay_counter = Signal(32) self._decay_counter = Signal(32)
# Control signals # Control signals
self.data = Signal(data_width) self.data = Signal(data_width)
@ -57,44 +57,47 @@ class PeakDetector(Module):
self.sync += If(~self.enable, self.sync += If(~self.enable,
# Reset halfway. ADCs are 0-2V, and everything should be centered at 1V, so this is approximating the initial value # Reset halfway. ADCs are 0-2V, and everything should be centered at 1V, so this is approximating the initial value
min_val.eq(int(2**data_width /2)), self._min_val.eq(int(2**data_width /2)),
max_val.eq(int(2**data_width /2)), self._max_val.eq(int(2**data_width /2)),
self.triggered.eq(0), self.triggered.eq(0),
decay_counter.eq(0), self._decay_counter.eq(0),
triggered_time.eq(0), self._triggered_time.eq(0),
) )
# Constantly updating diff to simplify some statements # Constantly updating self._diff to simplify some statements
self.comb += diff.eq(max_val - min_val) self.comb += self._diff.eq(self._max_val - self._min_val)
self.sync += If(self.enable & self.data_valid, self.sync += If(self.enable & self.data_valid,
# Decay should run irrespective of if we have triggered,
# and before everything else so it can be overwritten
self._decay_counter.eq(self._decay_counter + 1),
# Decay threshold has been reached, apply decay to peaks
If(self._decay_counter >= self.decay_period,
self._decay_counter.eq(0),
# Only apply decay if the values would not overlap, and we use the decay
If((self._diff >= (self.decay_value << 1)) & (self.decay_value > 0),
self._max_val.eq(self._max_val - self.decay_value),
self._min_val.eq(self._min_val + self.decay_value))),
# Update maximum value # Update maximum value
If(self.data > max_val, max_val.eq(self.data)), If(self.data > self._max_val, self._max_val.eq(self.data)),
# Update minimum value # Update minimum value
If(self.data < min_val, min_val.eq(self.data)), If(self.data < self._min_val, self._min_val.eq(self.data)),
If(diff > self.thresh_value, If(self._diff > self.thresh_value,
# We have met the threshold for triggering, start counting # We have met the threshold for triggering, start counting
triggered_time.eq(triggered_time + 1), self._triggered_time.eq(self._triggered_time + 1),
decay_counter.eq(0),
# We have triggered, so we can set the output. After this point, # We have triggered, so we can set the output. After this point,
# nothing we do matters until enable is de-asserted and we reset # nothing we do matters until enable is de-asserted and we reset
# triggered. # triggered.
If(triggered_time + 1 >= self.thresh_time, self.triggered.eq(1))) If(self._triggered_time + 1 >= self.thresh_time, self.triggered.eq(1)))
.Else( .Else(
# We have not met the threshold, reset timer and handle decay # We have not met the threshold, reset timer
triggered_time.eq(0), self._triggered_time.eq(0),
decay_counter.eq(decay_counter + 1), ),
# Decay threshold has been reached, apply decay to peaks
If(decay_counter >= self.decay_period,
decay_counter.eq(0),
# Only apply decay if the values would not overlap, and we use the decay
If((diff >= (self.decay_value << 1)) & (self.decay_value > 0),
max_val.eq(max_val - self.decay_value),
min_val.eq(min_val + self.decay_value)))
)
) )