litex/migen/corelogic/divider.py

43 lines
1.1 KiB
Python

from migen.fhdl import structure as f
class Inst:
def __init__(self, w):
self.w = w
d = partial(f.Declare, self)
d("start_i")
d("dividend_i", f.BV(w))
d("divisor_i", f.BV(w))
d("ready_o")
d("quotient_o", f.BV(w))
d("remainder_o", f.BV(w))
d("_qr", f.BV(2*w))
d("_counter", f.BV(f.BitsFor(w)))
d("_divisor_r", f.BV(w))
d("_diff", f.BV(w+1))
def GetFragment(self):
a = f.Assign
comb = [
a(self.quotient_o, self._qr[:self.w]),
a(self.remainder_o, self._qr[self.w:]),
a(self.ready_o, self._counter == f.Constant(0, self._counter.bv)),
a(self._diff, self.remainder_o - self._divisor_r)
]
sync = [
f.If(self.start_i == 1, [
a(self._counter, self.w),
a(self._qr, self.dividend_i),
a(self._divisor_r, self.divisor_i)
], [
f.If(self.ready_o == 0, [
f.If(self._diff[self.w] == 1,
[a(self._qr, f.Cat(0, self._qr[:2*self.w-1]))],
[a(self._qr, f.Cat(1, self._qr[:self.w-1], self._diff[:self.w]))]),
a(self._counter, self._counter - f.Constant(1, self._counter.bv)),
])
])
]
return f.Fragment(comb, sync)