ticks.py revision 13431:40bbea43ddf7 
1# Copyright (c) 2007 The Regents of The University of Michigan
2# All rights reserved.
3#
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5# modification, are permitted provided that the following conditions are
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7# notice, this list of conditions and the following disclaimer;
8# redistributions in binary form must reproduce the above copyright
9# notice, this list of conditions and the following disclaimer in the
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11# neither the name of the copyright holders nor the names of its
12# contributors may be used to endorse or promote products derived from
13# this software without specific prior written permission.
14#
15# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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26#
27# Authors: Nathan Binkert
28
29from __future__ import print_function
30
31import sys
32from m5.util import warn
33
34# fix the global frequency
35def fixGlobalFrequency():
36    import _m5.core
37    _m5.core.fixClockFrequency()
38
39def setGlobalFrequency(ticksPerSecond):
40    from m5.util import convert
41    import _m5.core
42
43    if isinstance(ticksPerSecond, (int, long)):
44        tps = ticksPerSecond
45    elif isinstance(ticksPerSecond, float):
46        tps = ticksPerSecond
47    elif isinstance(ticksPerSecond, str):
48        tps = round(convert.anyToFrequency(ticksPerSecond))
49    else:
50        raise TypeError, \
51              "wrong type '%s' for ticksPerSecond" % type(ticksPerSecond)
52    _m5.core.setClockFrequency(int(tps))
53
54# how big does a rounding error need to be before we warn about it?
55frequency_tolerance = 0.001  # 0.1%
56
57def fromSeconds(value):
58    import _m5.core
59
60    if not isinstance(value, float):
61        raise TypeError, "can't convert '%s' to type tick" % type(value)
62
63    # once someone needs to convert to seconds, the global frequency
64    # had better be fixed
65    if not _m5.core.clockFrequencyFixed():
66        raise AttributeError, \
67              "In order to do conversions, the global frequency must be fixed"
68
69    if value == 0:
70        return 0
71
72    # convert the value from time to ticks
73    value *= _m5.core.getClockFrequency()
74
75    int_value = int(round(value))
76    err = (value - int_value) / value
77    if err > frequency_tolerance:
78        warn("rounding error > tolerance\n    %f rounded to %d", value,
79            int_value)
80    return int_value
81
82__all__ = [ 'setGlobalFrequency', 'fixGlobalFrequency', 'fromSeconds',
83            'frequency_tolerance' ]
84