CSR bus definitions

migen/bus/csr.py

@@ -0,0 +1,35 @@
+from migen.fhdl import structure as f
+from functools import partial
+
+class Master:
+	def __init__(self):
+		d = partial(f.Declare, self)
+		d("a_o", f.BV(16))
+		d("we_o")
+		d("d_o", f.BV(32))
+		d("d_i", f.BV(32))
+
+class Slave:
+	def __init__(self):
+		d = partial(f.Declare, self)
+		d("a_i", f.BV(16))
+		d("we_i")
+		d("d_i", f.BV(32))
+		d("d_o", f.BV(32))
+
+class Interconnect:
+	def __init__(self, master, slaves):
+		self.master = master
+		self.slaves = slaves
+	
+	def GetFragment(self):
+		a = f.Assign
+		comb = []
+		rb = f.Constant(0, f.BV(32))
+		for slave in self.slaves:
+			comb.append(a(slave.a_i, self.master.a_o))
+			comb.append(a(slave.we_i, self.master.we_o))
+			comb.append(a(slave.d_i, self.master.d_o))
+			rb = rb | slave.d_o
+		comb.append(a(master.d_i, rb))
+		return f.Fragment(comb)

test.py

@@ -1,50 +0,0 @@
-from migen.fhdl import structure as f
-from migen.fhdl import verilog
-from functools import partial
-
-class Divider:
-	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)
-
-d = Divider(32)
-f = d.GetFragment()
-o = verilog.Convert(f, {d.start_i, d.dividend_i, d.divisor_i}, {d.ready_o, d.quotient_o, d.remainder_o})
-print(o)