litedram/test/test_bist.py

127 lines
3.7 KiB
Python

# This file is Copyright (c) 2016-2018 Florent Kermarrec <florent@enjoy-digital.fr>
# This file is Copyright (c) 2016 Tim 'mithro' Ansell <mithro@mithis.com>
# License: BSD
import unittest
import random
from migen import *
from litex.soc.interconnect.stream import *
from litedram.common import *
from litedram.frontend.bist import *
from litedram.frontend.bist import _LiteDRAMBISTGenerator
from litedram.frontend.bist import _LiteDRAMBISTChecker
from test.common import *
from litex.gen.sim import *
class GenCheckDriver:
def __init__(self, module):
self.module = module
def reset(self):
yield self.module.reset.eq(1)
yield
yield self.module.reset.eq(0)
yield
def run(self, base, length):
yield self.module.base.eq(base)
yield self.module.length.eq(length)
yield self.module.start.eq(1)
yield
yield self.module.start.eq(0)
yield
while((yield self.module.done) == 0):
yield
if hasattr(self.module, "errors"):
self.errors = (yield self.module.errors)
class TestBIST(unittest.TestCase):
def test_generator(self):
port = LiteDRAMNativeWritePort(address_width=32, data_width=32)
def main_generator(dut):
self.errors = 0
# test incr
yield dut.ce.eq(1)
yield dut.random_enable.eq(0)
yield
for i in range(1024):
data = (yield dut.o)
if data != i:
self.errors += 1
yield
# test random
datas = []
yield dut.ce.eq(1)
yield dut.random_enable.eq(1)
for i in range(1024):
data = (yield dut.o)
if data in datas:
self.errors += 1
datas.append(data)
yield
# dut
dut = Generator(23, n_state=23, taps=[17, 22])
# simulation
generators = [main_generator(dut)]
run_simulation(dut, main_generator(dut), vcd_name="generator.vcd")
self.assertEqual(self.errors, 0)
def test_bist(self):
class DUT(Module):
def __init__(self):
self.write_port = LiteDRAMNativeWritePort(address_width=32, data_width=32)
self.read_port = LiteDRAMNativeReadPort(address_width=32, data_width=32)
self.submodules.generator = _LiteDRAMBISTGenerator(self.write_port)
self.submodules.checker = _LiteDRAMBISTChecker(self.read_port)
def main_generator(dut, mem):
generator = GenCheckDriver(dut.generator)
checker = GenCheckDriver(dut.checker)
# write
yield from generator.reset()
yield from generator.run(16, 64)
# read (no errors)
yield from checker.reset()
yield from checker.run(16, 64)
assert checker.errors == 0
# corrupt memory (using generator)
yield from generator.reset()
yield from generator.run(16 + 60, 64)
# read (4 errors)
yield from checker.reset()
yield from checker.run(16, 64)
assert checker.errors != 0
# read (no errors)
yield from checker.reset()
yield from checker.run(16 + 60, 64)
assert checker.errors == 0
# dut
dut = DUT()
mem = DRAMMemory(32, 128)
# simulation
generators = [
main_generator(dut, mem),
mem.write_handler(dut.write_port),
mem.read_handler(dut.read_port)
]
run_simulation(dut, generators, vcd_name="bist.vcd")