litedram/test/test_bist.py

136 lines
3.2 KiB
Python
Executable File

import unittest
import random
from litex.gen import *
from litex.soc.interconnect.stream import *
from litedram.common import LiteDRAMWritePort, LiteDRAMReadPort
from litedram.frontend.bist import _LiteDRAMBISTGenerator
from litedram.frontend.bist import _LiteDRAMBISTChecker
from test.common import *
class DUT(Module):
def __init__(self):
self.write_port = LiteDRAMWritePort(aw=32, dw=32)
self.read_port = LiteDRAMReadPort(aw=32, dw=32)
self.submodules.generator = _LiteDRAMBISTGenerator(self.write_port, False)
self.submodules.checker = _LiteDRAMBISTChecker(self.read_port, False)
def main_generator(dut, mem):
# write
yield dut.generator.reset.eq(1)
yield
yield dut.generator.reset.eq(0)
yield
yield dut.generator.base.eq(16)
yield dut.generator.length.eq(64)
for i in range(8):
yield
yield dut.generator.start.eq(1)
yield
yield dut.generator.start.eq(0)
for i in range(8):
yield
while((yield dut.generator.done) == 0):
yield
done = yield dut.generator.done
assert done, done
# read (no errors)
yield dut.checker.reset.eq(1)
yield
yield dut.checker.reset.eq(0)
yield
yield dut.checker.base.eq(16)
yield dut.checker.length.eq(64)
for i in range(8):
yield
yield dut.checker.start.eq(1)
yield
yield dut.checker.start.eq(0)
yield
while True:
done = (yield dut.checker.done)
if not done:
yield
else:
break
assert done, done
errors = yield dut.checker.err_count
assert errors == 0, errors
# corrupt memory (4 errors)
for i in range(4):
mem.mem[i+16] = ~mem.mem[i+16]
# read (4 errors)
yield dut.checker.reset.eq(1)
yield
yield dut.checker.reset.eq(0)
yield
yield dut.checker.base.eq(16)
yield dut.checker.length.eq(64)
yield dut.checker.start.eq(1)
yield
yield dut.checker.start.eq(0)
yield
while True:
done = (yield dut.checker.done)
if not done:
yield
else:
break
assert done, done
errors = yield dut.checker.err_count
assert errors == 4, errors
# revert memory
for i in range(4):
mem.mem[i+16] = ~mem.mem[i+16]
# read (no errors)
yield dut.checker.reset.eq(1)
yield
yield dut.checker.reset.eq(0)
yield
yield dut.checker.base.eq(16)
yield dut.checker.length.eq(64)
for i in range(8):
yield
yield dut.checker.start.eq(1)
yield
yield dut.checker.start.eq(0)
yield
while True:
done = (yield dut.checker.done)
if not done:
yield
else:
break
assert done, done
errors = yield dut.checker.err_count
assert errors == 0, errors
class TestBIST(unittest.TestCase):
def test(self):
dut = DUT()
mem = DRAMMemory(32, 128)
generators = {
"sys" : [
main_generator(dut, mem),
mem.write_generator(dut.write_port),
mem.read_generator(dut.read_port)
]
}
clocks = {"sys": 10}
run_simulation(dut, generators, clocks, vcd_name="sim.vcd")