corelogic: MC divider module

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)