XBar.py (10405:7a618c07e663) XBar.py (10719:b4fc9ad648aa)
1# Copyright (c) 2012 ARM Limited
1# Copyright (c) 2012, 2015 ARM Limited
2# All rights reserved.
3#
4# The license below extends only to copyright in the software and shall
5# not be construed as granting a license to any other intellectual
6# property including but not limited to intellectual property relating
7# to a hardware implementation of the functionality of the software
8# licensed hereunder. You may use the software subject to the license
9# terms below provided that you ensure that this notice is replicated

--- 34 unchanged lines hidden (view full) ---

44from m5.params import *
45from m5.proxy import *
46from m5.SimObject import SimObject
47
48class BaseXBar(MemObject):
49 type = 'BaseXBar'
50 abstract = True
51 cxx_header = "mem/xbar.hh"
2# All rights reserved.
3#
4# The license below extends only to copyright in the software and shall
5# not be construed as granting a license to any other intellectual
6# property including but not limited to intellectual property relating
7# to a hardware implementation of the functionality of the software
8# licensed hereunder. You may use the software subject to the license
9# terms below provided that you ensure that this notice is replicated

--- 34 unchanged lines hidden (view full) ---

44from m5.params import *
45from m5.proxy import *
46from m5.SimObject import SimObject
47
48class BaseXBar(MemObject):
49 type = 'BaseXBar'
50 abstract = True
51 cxx_header = "mem/xbar.hh"
52 slave = VectorSlavePort("vector port for connecting masters")
53 master = VectorMasterPort("vector port for connecting slaves")
54 header_cycles = Param.Cycles(1, "cycles of overhead per transaction")
55 width = Param.Unsigned(8, "xbar width (bytes)")
56
52
53 slave = VectorSlavePort("Vector port for connecting masters")
54 master = VectorMasterPort("Vector port for connecting slaves")
55
56 # Latencies governing the time taken for the variuos paths a
57 # packet has through the crossbar. Note that the crossbar itself
58 # does not add the latency due to assumptions in the coherency
59 # mechanism. Instead the latency is annotated on the packet and
60 # left to the neighbouring modules.
61 #
62 # A request incurs the frontend latency, possibly snoop filter
63 # lookup latency, and forward latency. A response incurs the
64 # response latency. Frontend latency encompasses arbitration and
65 # deciding what to do when a request arrives. the forward latency
66 # is the latency involved once a decision is made to forward the
67 # request. The response latency, is similar to the forward
68 # latency, but for responses rather than requests.
69 frontend_latency = Param.Cycles(3, "Frontend latency")
70 forward_latency = Param.Cycles(4, "Forward latency")
71 response_latency = Param.Cycles(2, "Response latency")
72
73 # Width governing the throughput of the crossbar
74 width = Param.Unsigned(8, "Datapath width per port (bytes)")
75
57 # The default port can be left unconnected, or be used to connect
58 # a default slave port
59 default = MasterPort("Port for connecting an optional default slave")
60
61 # The default port can be used unconditionally, or based on
62 # address range, in which case it may overlap with other
63 # ports. The default range is always checked first, thus creating
64 # a two-level hierarchical lookup. This is useful e.g. for the PCI

--- 4 unchanged lines hidden (view full) ---

69class NoncoherentXBar(BaseXBar):
70 type = 'NoncoherentXBar'
71 cxx_header = "mem/noncoherent_xbar.hh"
72
73class CoherentXBar(BaseXBar):
74 type = 'CoherentXBar'
75 cxx_header = "mem/coherent_xbar.hh"
76
76 # The default port can be left unconnected, or be used to connect
77 # a default slave port
78 default = MasterPort("Port for connecting an optional default slave")
79
80 # The default port can be used unconditionally, or based on
81 # address range, in which case it may overlap with other
82 # ports. The default range is always checked first, thus creating
83 # a two-level hierarchical lookup. This is useful e.g. for the PCI

--- 4 unchanged lines hidden (view full) ---

88class NoncoherentXBar(BaseXBar):
89 type = 'NoncoherentXBar'
90 cxx_header = "mem/noncoherent_xbar.hh"
91
92class CoherentXBar(BaseXBar):
93 type = 'CoherentXBar'
94 cxx_header = "mem/coherent_xbar.hh"
95
96 # The coherent crossbar additionally has snoop responses that are
97 # forwarded after a specific latency.
98 snoop_response_latency = Param.Cycles(4, "Snoop response latency")
99
100 # An optional snoop filter
101 snoop_filter = Param.SnoopFilter(NULL, "Selected snoop filter")
102
77 system = Param.System(Parent.any, "System that the crossbar belongs to.")
103 system = Param.System(Parent.any, "System that the crossbar belongs to.")
78 snoop_filter = Param.SnoopFilter(NULL, "Selected snoop filter.")
79
80class SnoopFilter(SimObject):
81 type = 'SnoopFilter'
82 cxx_header = "mem/snoop_filter.hh"
104
105class SnoopFilter(SimObject):
106 type = 'SnoopFilter'
107 cxx_header = "mem/snoop_filter.hh"
83 lookup_latency = Param.Cycles(3, "lookup latency (cycles)")
84
108
109 # Lookup latency of the snoop filter, added to requests that pass
110 # through a coherent crossbar.
111 lookup_latency = Param.Cycles(1, "Lookup latency")
112
85 system = Param.System(Parent.any, "System that the crossbar belongs to.")
113 system = Param.System(Parent.any, "System that the crossbar belongs to.")