corelogic: MC divider module

diff --git a/migen/corelogic/divider.py b/migen/corelogic/divider.py
new file mode 100644 (file)
index 0000000..e19ffc2
--- /dev/null
+++ b/migen/corelogic/divider.py
@@ -0,0 +1,43 @@
+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)
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