ticks.py revision 12563:8d59ed22ae79
1# Copyright (c) 2007 The Regents of The University of Michigan 2# All rights reserved. 3# 4# Redistribution and use in source and binary forms, with or without 5# modification, are permitted provided that the following conditions are 6# met: redistributions of source code must retain the above copyright 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 10# documentation and/or other materials provided with the distribution; 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 17# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 18# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 19# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 21# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 25# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26# 27# Authors: Nathan Binkert 28 29from __future__ import print_function 30 31import sys 32from m5.util import warn 33 34tps = 1.0e12 # default to 1 THz (1 Tick == 1 ps) 35tps_fixed = False # once set to true, can't be changed 36 37# fix the global frequency and tell C++ about it 38def fixGlobalFrequency(): 39 import _m5.core 40 global tps, tps_fixed 41 if not tps_fixed: 42 tps_fixed = True 43 _m5.core.setClockFrequency(int(tps)) 44 print("Global frequency set at %d ticks per second" % int(tps)) 45 46def setGlobalFrequency(ticksPerSecond): 47 from m5.util import convert 48 49 global tps, tps_fixed 50 51 if tps_fixed: 52 raise AttributeError, \ 53 "Global frequency already fixed at %f ticks/s." % tps 54 55 if isinstance(ticksPerSecond, (int, long)): 56 tps = ticksPerSecond 57 elif isinstance(ticksPerSecond, float): 58 tps = ticksPerSecond 59 elif isinstance(ticksPerSecond, str): 60 tps = round(convert.anyToFrequency(ticksPerSecond)) 61 else: 62 raise TypeError, \ 63 "wrong type '%s' for ticksPerSecond" % type(ticksPerSecond) 64 65# how big does a rounding error need to be before we warn about it? 66frequency_tolerance = 0.001 # 0.1% 67 68def fromSeconds(value): 69 if not isinstance(value, float): 70 raise TypeError, "can't convert '%s' to type tick" % type(value) 71 72 # once someone needs to convert to seconds, the global frequency 73 # had better be fixed 74 if not tps_fixed: 75 raise AttributeError, \ 76 "In order to do conversions, the global frequency must be fixed" 77 78 if value == 0: 79 return 0 80 81 # convert the value from time to ticks 82 value *= tps 83 84 int_value = int(round(value)) 85 err = (value - int_value) / value 86 if err > frequency_tolerance: 87 warn("rounding error > tolerance\n %f rounded to %d", value, 88 int_value) 89 return int_value 90 91__all__ = [ 'setGlobalFrequency', 'fixGlobalFrequency', 'fromSeconds', 92 'frequency_tolerance' ] 93