litedram/test/test_bist.py

211 lines
7.2 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, end=None):
if end is None:
end = base + 0x100000
yield self.module.base.eq(base)
yield self.module.end.eq(end)
yield self.module.length.eq(length)
yield self.module.run.eq(1)
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, generators)
self.assertEqual(self.errors, 0)
def bist_generator_test(self, data_width, base, length, end, mem_depth, init_generator=None):
end_addr = base + length
start_word = base // (data_width//8)
end_word = end_addr // (data_width//8)
n_words = end_word - start_word
class DUT(Module):
def __init__(self):
self.write_port = LiteDRAMNativeWritePort(address_width=32, data_width=data_width)
self.submodules.generator = _LiteDRAMBISTGenerator(self.write_port)
self.mem = DRAMMemory(data_width, mem_depth)
def main_generator(dut):
generator = GenCheckDriver(dut.generator)
if init_generator is not None:
yield from init_generator(dut)
yield from generator.reset()
yield from generator.run(base, length, end=end)
yield
dut = DUT()
generators = [
main_generator(dut),
dut.mem.write_handler(dut.write_port),
]
return dut, generators
def test_bist_generator(self):
dut, generators = self.bist_generator_test(mem_depth=128, data_width=32, end=128 * 4,
base=16, length=64)
run_simulation(dut, generators)
before = 16 // 4
mem_expected = [0] * before + list(range(64//4)) + [0] * (128 - 64//4 - before)
self.assertEqual(dut.mem.mem, mem_expected)
def test_bist_generator_random_data(self):
def init(dut):
yield dut.generator.random_data.eq(1)
yield
# fill whole memory
dut, generators = self.bist_generator_test(mem_depth=128, data_width=32, end=128 * 4,
base=0, length=128 * 4, init_generator=init)
run_simulation(dut, generators)
# only check if there are no duplicates and if data is not a simple sequence
self.assertEqual(len(set(dut.mem.mem)), len(dut.mem.mem), msg='Duplicate values in memory')
self.assertNotEqual(dut.mem.mem, list(range(128)), msg='Values are a sequence')
def test_bist_generator_random_addr(self): # write whole memory and check if there are no repetitions?
def init(dut):
yield dut.generator.random_addr.eq(1)
yield
# fill whole memory
dut, generators = self.bist_generator_test(mem_depth=128, data_width=32, end=128 * 4,
base=0, length=128 * 4, init_generator=init)
run_simulation(dut, generators)
# with random address and address wrapping (generator.end) we _can_ have duplicates
# we can at least check that the values written are not an ordered sequence
self.assertNotEqual(dut.mem.mem, list(range(128)), msg='Values are a sequence')
def test_bist_generator_wraps_addr(self):
dut, generators = self.bist_generator_test(mem_depth=128, data_width=32,
base=16, length=96, end=32)
run_simulation(dut, generators)
# we restrict address to <16, 32) and write 96 bytes (which results in 96/4=24 words generated)
# this means that the address should wrap and last 8 generated words should overwrite memory
# at address <16, 24)
before = 16 // 4
mem_expected = [0] * 4 + list(range(16)) + [0] * (128 - 4 - 16)
mem_expected[4:4+8] = list(range(16, 24))
self.assertEqual(dut.mem.mem, mem_expected)
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)