--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/python/ppci/target/token.py	Sat Mar 01 15:40:31 2014 +0100
@@ -0,0 +1,56 @@
+
+import struct
+
+def u16(h):
+    return struct.pack('<H', h)
+
+
+def u32(x):
+    return struct.pack('<I', x)
+
+
+def val2bit(v, bits):
+    b = []
+    for i in range(bits):
+        b.append(bool((1<<i) & v))
+    #b.reverse()
+    return b
+
+
+def bit_range(b, e):
+    """ Property generator function """
+    getter = lambda s: s[b:e]
+    def setter(s, v):
+        s[b:e] = v
+    return property(getter, setter)
+
+
+class Token:
+    def __init__(self, bitsize):
+        self.bitsize = bitsize
+        self.bit_value = 0
+
+    def set_bit(self, i, value):
+        value = bool(value)
+        assert i in range(0, self.bitsize)
+        mask = 1 << i
+        if value:
+            self.bit_value |= mask
+        else:
+            self.bit_value &= (~mask)
+
+    def __getitem__(self, key):
+        return False
+
+    def __setitem__(self, key, value):
+        if type(key) is int:
+            self.set_bit(key, value)
+        elif type(key) is slice:
+            assert key.step is None
+            bits = key.stop - key.start
+            value_bits = val2bit(value, bits)
+            for i in range(key.start, key.stop):
+                self.set_bit(i, value_bits[i - key.start])
+        else:
+            raise KeyError()
+