1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
# This file is part of the myhdl library, a Python package for using
# Python as a Hardware Description Language.
#
# Copyright (C) 2003-2011 Jan Decaluwe
#
# The myhdl library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public License as
# published by the Free Software Foundation; either version 2.1 of the
# License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
""" Module with the modbv class """
from __future__ import absolute_import
from ._intbv import intbv
from ._compat import long
class modbv(intbv):
__slots__ = []
def _handleBounds(self):
lo, hi, val = self._min, self._max, self._val
if lo is not None:
if val < lo or val >= hi:
self._val = (val - lo) % (hi - lo) + lo
def __repr__(self):
return "modbv(" + repr(self._val) + ")"
# indexing and slicing methods
# dedicated for modbv to support "declaration by slicing"
def __getitem__(self, key):
if isinstance(key, slice):
i, j = key.start, key.stop
if j is None: # default
j = 0
j = int(j)
if j < 0:
raise ValueError("modbv[i:j] requires j >= 0\n"
" j == %s" % j)
if i is None: # default
return modbv(self._val >> j)
i = int(i)
if i <= j:
raise ValueError("modbv[i:j] requires i > j\n"
" i, j == %s, %s" % (i, j))
res = modbv((self._val & (long(1) << i) - 1) >> j, _nrbits=i - j)
return res
else:
i = int(key)
res = bool((self._val >> i) & 0x1)
return res
|
