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wrpll: fix mulshift (2)

This commit is contained in:
Sebastien Bourdeauducq 2020-10-17 00:32:02 +08:00
parent 3f076bf79b
commit d185f1ac67
1 changed files with 9 additions and 6 deletions
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15
artiq/gateware/drtio/wrpll/thls.py
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@ -400,8 +400,11 @@ class NopUnit(BaseUnit):
class OpUnit(BaseUnit):
def __init__(self, op, data_width, stages):
def __init__(self, op, data_width, stages, op_data_width=None):
BaseUnit.__init__(self, data_width)
# work around Migen's mishandling of Verilog's cretinous operator width rules
if op_data_width is None:
op_data_width = data_width
if stages > 1:
# Vivado backward retiming for DSP does not work correctly if DSP inputs
@ -419,10 +422,11 @@ class OpUnit(BaseUnit):
i0, i1, stb_i = self.i0, self.i1, self.stb_i
output_stages = stages
o = op(i0, i1)
o = Signal((op_data_width, True))
self.comb += o.eq(op(i0, i1))
stb_o = stb_i
for i in range(output_stages):
n_o = Signal(data_width)
n_o = Signal((data_width, True))
if stages > 1:
n_o.attr.add(("retiming_backward", 1))
n_stb_o = Signal()
@ -552,9 +556,8 @@ class ProcessorImpl(Module):
if pd.multiplier_shifts:
if len(pd.multiplier_shifts) != 1:
raise NotImplementedError
# work around Migen's mishandling of Verilog's cretinous operator width rules
multiplier = OpUnit(lambda a, b: Cat(a, C(0, pd.data_width)) * Cat(b, C(0, pd.data_width)) >> pd.multiplier_shifts[0],
pd.data_width, pd.multiplier_stages)
multiplier = OpUnit(lambda a, b: a * b >> pd.multiplier_shifts[0],
pd.data_width, pd.multiplier_stages, op_data_width=2*pd.data_width)
else:
multiplier = NopUnit(pd.data_width)
minu = SelectUnit(operator.lt, pd.data_width)