litedram/test/test_refresh.py

102 lines
3.3 KiB
Python

# This file is Copyright (c) 2019 Florent Kermarrec <florent@enjoy-digital.fr>
# License: BSD
import unittest
from migen import *
from litedram.core.multiplexer import cmd_request_rw_layout
from litedram.core.refresher import RefreshSequencer, RefreshTimer, Refresher
def c2bool(c):
return {"-": 1, "_": 0}[c]
class TestRefresh(unittest.TestCase):
def refresh_sequencer_test(self, trp, trfc, starts, dones, cmds):
cmd = Record(cmd_request_rw_layout(a=16, ba=3))
def generator(dut):
dut.errors = 0
for start, done, cas, ras in zip(starts, dones, cmds.cas, cmds.ras):
yield dut.start.eq(c2bool(start))
yield
if (yield dut.done) != c2bool(done):
dut.errors += 1
if (yield cmd.cas) != c2bool(cas):
dut.errors += 1
if (yield cmd.ras) != c2bool(ras):
dut.errors += 1
dut = RefreshSequencer(cmd, trp, trfc)
run_simulation(dut, [generator(dut)])
self.assertEqual(dut.errors, 0)
def test_refresh_sequencer(self):
trp = 1
trfc = 2
class Obj: pass
cmds = Obj()
starts = "_-______________"
cmds.cas = "___-____________"
cmds.ras = "__--____________"
dones = "_____-__________"
self.refresh_sequencer_test(trp, trfc, starts, dones, cmds)
def refresh_timer_test(self, trefi):
def generator(dut):
dut.errors = 0
for i in range(16*trefi):
if i%trefi == (trefi - 1):
if (yield dut.refresh.done) != 1:
dut.errors += 1
else:
if (yield dut.refresh.done) != 0:
dut.errors += 1
yield
class DUT(Module):
def __init__(self, trefi):
self.submodules.refresh = RefreshTimer(trefi)
self.comb += self.refresh.wait.eq(~self.refresh.done)
dut = DUT(trefi)
run_simulation(dut, [generator(dut)])
self.assertEqual(dut.errors, 0)
def test_refresh_timer(self):
for i in range(1, 32):
self.refresh_timer_test(i)
def test_refresher(self):
class Obj: pass
settings = Obj()
settings.with_refresh = True
settings.timing = Obj()
settings.timing.tREFI = 64
settings.timing.tRP = 1
settings.timing.tRFC = 2
settings.geom = Obj()
settings.geom.addressbits = 16
settings.geom.bankbits = 3
settings.phy = Obj()
settings.phy.nranks = 1
def generator(dut):
dut.errors = 0
yield dut.cmd.ready.eq(1)
for i in range(16):
while (yield dut.cmd.valid) == 0:
yield
cmd_valid_gap = 0
while (yield dut.cmd.valid) == 1:
cmd_valid_gap += 1
yield
while (yield dut.cmd.valid) == 0:
cmd_valid_gap += 1
yield
if cmd_valid_gap != settings.timing.tREFI:
dut.errors += 1
dut = Refresher(settings)
run_simulation(dut, [generator(dut)])
self.assertEqual(dut.errors, 0)