src/mem/XBar.py

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# Authors: Nathan Binkert
#          Andreas Hansson

from MemObject import MemObject
from System import System
from m5.params import *
from m5.proxy import *
from m5.SimObject import SimObject

class BaseXBar(MemObject):
    type = 'BaseXBar'
    abstract = True
    cxx_header = "mem/xbar.hh"
    slave = VectorSlavePort("vector port for connecting masters")
    master = VectorMasterPort("vector port for connecting slaves")
    header_cycles = Param.Cycles(1, "cycles of overhead per transaction")
    width = Param.Unsigned(8, "xbar width (bytes)")

    # The default port can be left unconnected, or be used to connect
    # a default slave port
    default = MasterPort("Port for connecting an optional default slave")

    # The default port can be used unconditionally, or based on
    # address range, in which case it may overlap with other
    # ports. The default range is always checked first, thus creating
    # a two-level hierarchical lookup. This is useful e.g. for the PCI
    # xbar configuration.
    use_default_range = Param.Bool(False, "Perform address mapping for " \
                                       "the default port")

class NoncoherentXBar(BaseXBar):
    type = 'NoncoherentXBar'
    cxx_header = "mem/noncoherent_xbar.hh"

class CoherentXBar(BaseXBar):
    type = 'CoherentXBar'
    cxx_header = "mem/coherent_xbar.hh"

    system = Param.System(Parent.any, "System that the crossbar belongs to.")
    snoop_filter = Param.SnoopFilter(NULL, "Selected snoop filter.")

class SnoopFilter(SimObject):
    type = 'SnoopFilter'
    cxx_header = "mem/snoop_filter.hh"
    lookup_latency = Param.Cycles(3, "lookup latency (cycles)")

    system = Param.System(Parent.any, "System that the crossbar belongs to.")