xref: /gem5/src/sim/DVFSHandler.py

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# Authors: Vasileios Spiliopoulos
#          Akash Bagdia

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

# The handler in its current form is design to be centeralized, one per system
# and manages all the source clock domains (SrcClockDomain) it is configured to
# handle.  The specific voltage and frequency points are configured per clock
# and voltage domain.
class DVFSHandler(SimObject):
    type = 'DVFSHandler'
    cxx_header = "sim/dvfs_handler.hh"

    # List of controllable clock domains which in turn reference the appropriate
    # voltage domains
    domains = VectorParam.SrcClockDomain([], "list of domains")

    # System domain (its clock and voltage) is not controllable
    sys_clk_domain = Param.SrcClockDomain(Parent.clk_domain,
                         "Clk domain in which the handler is instantiated")

    enable = Param.Bool(False, "Enable/Disable the handler")

    # The transition latency depends on how much time the PLLs and voltage
    # regualators takes to migrate from current levels to the new level, is
    # usally variable and hardware implementation dependent. In order to
    # accomodate this effect with ease, we provide a fixed transition latency
    # associated with all migrations. Configure this to maximum latency that
    # the hardware will take to migratate between any two perforamnce levels.
    transition_latency = Param.Latency('100us',
                             "fixed latency for perf level migration")