TrafficGen.py revision 9720:090935b1b797 
1# Copyright (c) 2012 ARM Limited
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35#
36# Authors: Thomas Grass
37#          Andreas Hansson
38#          Sascha Bischoff
39
40from m5.params import *
41from m5.proxy import *
42from MemObject import MemObject
43
44# The traffic generator is a master module that generates stimuli for
45# the memory system, based on a collection of simple behaviours that
46# are either probabilistic or based on traces. It can be used stand
47# alone for creating test cases for interconnect and memory
48# controllers, or function as a black-box replacement for system
49# components that are not yet modelled in detail, e.g. a video engine
50# or baseband subsystem in an SoC.
51#
52# The traffic generator has a single master port that is used to send
53# requests, independent of the specific behaviour. The behaviour of
54# the traffic generator is specified in a configuration file, and this
55# file describes a state transition graph where each state is a
56# specific generator behaviour. Examples include idling, generating
57# linear address sequences, random sequences and replay of captured
58# traces. By describing these behaviours as states, it is straight
59# forward to create very complex behaviours, simply by arranging them
60# in graphs. The graph transitions can also be annotated with
61# probabilities, effectively making it a Markov Chain.
62class TrafficGen(MemObject):
63    type = 'TrafficGen'
64    cxx_header = "cpu/testers/traffic_gen/traffic_gen.hh"
65
66    # Port used for sending requests and receiving responses
67    port = MasterPort("Master port")
68
69    # Config file to parse for the state descriptions
70    config_file = Param.String("Configuration file describing the behaviour")
71
72    # System used to determine the mode of the memory system
73    system = Param.System(Parent.any, "System this generator is part of")
74
75    # Should requests respond to back-pressure or not, if true, the
76    # rate of the traffic generator will be slowed down if requests
77    # are not immediately accepted
78    elastic_req = Param.Bool(False,
79                             "Slow down requests in case of backpressure")
80