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56 lines
1.5 KiB
Python

from amaranth import *
from amaranth.asserts import *
from power_fv.check import PowerFVCheck
from power_fv.check._timer import Timer
__all__ = ["LivenessCheck"]
class LivenessCheck(PowerFVCheck, name=("liveness",)):
"""Liveness check.
Checks that a core does not hang for the duration of the bounded-model check.
"""
def testbench(self):
return LivenessTestbench(self)
class LivenessTestbench(Elaboratable):
def __init__(self, check):
if not isinstance(check, LivenessCheck):
raise TypeError("Check must be an instance of LivenessCheck, not {!r}"
.format(check))
self.check = check
self.name = "liveness_tb"
def elaborate(self, platform):
m = Module()
m.submodules.t_pre = t_pre = Timer(self.check.skip - 1)
m.submodules.t_post = t_post = Timer(self.check.depth - 1)
m.submodules.dut = dut = self.check.dut
curr_order = AnyConst(dut.pfv.order.shape())
next_order = curr_order + 1
next_retired = Signal()
with m.If(Rose(t_pre.zero)):
m.d.comb += [
Assume(dut.pfv.stb),
Assume(curr_order == dut.pfv.order),
]
with m.Elif(t_pre.zero):
with m.If(dut.pfv.stb & (dut.pfv.order == next_order)):
m.d.sync += next_retired.eq(1)
with m.If(t_post.zero):
m.d.comb += Assert(next_retired)
m.d.comb += Assert(~Past(t_post.zero))
return m