add MigIo Class

migScope/migIo.py

@@ -0,0 +1,27 @@
+from migen.fhdl.structure import *
+from migen.bus import csr
+from migen.bank import description, csrgen
+from migen.bank.description import *
+
+
+class MigIo:
+	def __init__(self, width, mode = "IO"):
+		self.width = width
+		self.mode = mode
+		self.ireg = description.RegisterField("i", 0, READ_ONLY, WRITE_ONLY)
+		self.oreg = description.RegisterField("o", 0)
+		if "I" in self.mode:
+			self.i = Signal(BV(self.width))
+			self.ireg = description.RegisterField("i", self.width, READ_ONLY, WRITE_ONLY)
+			self.ireg.field.w.name_override = "inputs"
+		if "O" in self.mode:
+			self.o = Signal(BV(self.width))
+			self.oreg = description.RegisterField("o", self.width)
+			self.oreg.field.r.name_override = "ouptuts"
+		self.bank = csrgen.Bank([self.oreg, self.ireg])
+
+	def get_fragment(self):
+		comb = []
+		comb += [self.ireg.field.w.eq(self.i)]
+		comb += [self.o.eq(self.oreg.field.r)]		
+		return Fragment(comb=comb) + self.bank.get_fragment()