initial support for Bus types

bs/BusTypes.bs

@@ -0,0 +1,33 @@
+package BusTypes(BusVal, TransactionSize) where
+
+import Types
+
+data BusError
+    = UnMapped
+    | UnAligned
+    deriving (Bits, Eq, FShow)
+
+data TransactionSize
+    = SizeByte
+    | SizeHalfWord
+    | SizeFullWord
+    | SizeDoubleWord
+    | SizeQuadWord
+    deriving (Bits, Eq, FShow)
+
+data BusVal
+    = BusByte Byte
+    | BusHalfWord HalfWord
+    | BusFullWord FullWord
+    | BusDoubleWord DoubleWord
+    | BusQuadWord QuadWord
+    deriving (Bits, Eq, FShow)
+
+data ReadRequest = ReadRequest Addr TransactionSize
+    deriving (Bits, Eq, FShow)
+
+data WriteRequest = WriteRequest Addr BusVal
+    deriving (Bits, Eq, FShow)
+
+a :: UInt 5
+a = 3