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sawg/limiter: make signed signals explicitly

This commit is contained in:
Robert Jördens 2017-06-22 13:44:36 +02:00
parent 53be34a25f
commit d0cf0f2b87
1 changed files with 15 additions and 11 deletions
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26
artiq/gateware/dsp/sawg.py
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@ -88,13 +88,12 @@ class Config(Module):
self.iq_en = Signal(2, reset=0b01)
self.limits = [[Signal((width, True)), Signal((width, True))]
for i in range(2)]
limit = 1 << width - 1
limit = (1 << width - 1) - 1
limit_cordic = int(limit/cordic_gain)
self.limits[0][0].reset = Constant(-limit, (width, True))
self.limits[0][1].reset = Constant(limit - 1, (width, True))
self.limits[1][0].reset = Constant(int(-limit/cordic_gain),
(width, True))
self.limits[1][1].reset = Constant(int((limit - 1)/cordic_gain),
(width, True))
self.limits[0][1].reset = Constant(limit, (width, True))
self.limits[1][0].reset = Constant(-limit_cordic, (width, True))
self.limits[1][1].reset = Constant(limit_cordic, (width, True))
# TODO make persistent, add read-out/notification/clear
self.clipped = [Signal(2) for i in range(2)]
self.i = Endpoint([("addr", bits_for(4 + 2*len(self.limits) - 1)),
@ -187,15 +186,20 @@ class Channel(Module, SatAddMixin):
hbf[0].i.eq(self.sat_add(a1.xo[0], a2.xo[0],
limits=cfg.limits[1], clipped=cfg.clipped[1])),
hbf[1].i.eq(self.sat_add(a1.yo[0], a2.yo[0],
limits=cfg.limits[1], clipped=None)), # ignore Q clip data
limits=cfg.limits[1], clipped=cfg.clipped[1])),
]
# wire up outputs and q_{i,o} exchange
for o, x, y in zip(self.o, b.xo, self.y_in):
o_offset = Signal.like(o)
o_x = Signal.like(x)
o_y = Signal.like(y)
self.comb += [
o_offset.eq(u.o.a0[-len(o):]),
o_x.eq(Mux(cfg.iq_en[0], x, 0)),
o_y.eq(Mux(cfg.iq_en[1], y, 0)),
]
self.sync += [
o.eq(self.sat_add(
u.o.a0[-len(o):],
Mux(cfg.iq_en[0], x, 0),
Mux(cfg.iq_en[1], y, 0),
o.eq(self.sat_add(o_offset, o_x, o_y,
limits=cfg.limits[0],
clipped=cfg.clipped[0])),
]