32 lines
822 B
Python
32 lines
822 B
Python
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from nmigen import *
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__all__ = ["Adder"]
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class Adder(Elaboratable):
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def __init__(self):
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self.sub = Signal()
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self.src1 = Signal(32)
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self.src2 = Signal(32)
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self.result = Signal(32)
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self.carry = Signal()
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self.overflow = Signal()
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def elaborate(self, platform):
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m = Module()
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with m.If(self.sub):
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m.d.comb += [
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Cat(self.result, self.carry).eq(self.src1 - self.src2),
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self.overflow.eq((self.src1[-1] != self.src2[-1]) & (self.result[-1] == self.src2[-1]))
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]
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with m.Else():
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m.d.comb += [
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Cat(self.result, self.carry).eq(self.src1 + self.src2),
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self.overflow.eq(~self.src1[-1] & self.src2[-1] & self.result[-1])
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]
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return m
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