# # This file is part of LiteDRAM. # # Copyright (c) 2020 Antmicro # SPDX-License-Identifier: BSD-2-Clause import unittest from migen import * from litex.soc.interconnect import stream from litedram.common import * from litedram.phy import dfi from litedram.core.multiplexer import _Steerer from litedram.core.multiplexer import STEER_NOP, STEER_CMD, STEER_REQ, STEER_REFRESH from test.common import CmdRequestRWDriver class SteererDUT(Module): def __init__(self, nranks, dfi_databits, nphases): a, ba = 13, 3 nop = Record(cmd_request_layout(a=a, ba=ba)) choose_cmd = stream.Endpoint(cmd_request_rw_layout(a=a, ba=ba)) choose_req = stream.Endpoint(cmd_request_rw_layout(a=a, ba=ba)) refresher_cmd = stream.Endpoint(cmd_request_rw_layout(a=a, ba=ba)) self.commands = [nop, choose_cmd, choose_req, refresher_cmd] self.dfi = dfi.Interface(addressbits=a, bankbits=ba, nranks=nranks, databits=dfi_databits, nphases=nphases) self.submodules.steerer = _Steerer(self.commands, self.dfi) # NOP is not an endpoint and does not have is_* signals self.drivers = [CmdRequestRWDriver(req, i, ep_layout=i != 0, rw_layout=i != 0) for i, req in enumerate(self.commands)] class TestSteerer(unittest.TestCase): def test_nop_not_valid(self): # If NOP is selected then there should be no command selected on cas/ras/we. def main_generator(dut): # NOP on both phases yield dut.steerer.sel[0].eq(STEER_NOP) yield dut.steerer.sel[1].eq(STEER_NOP) yield from dut.drivers[0].nop() yield for i in range(2): cas_n = (yield dut.dfi.phases[i].cas_n) ras_n = (yield dut.dfi.phases[i].ras_n) we_n = (yield dut.dfi.phases[i].we_n) self.assertEqual((cas_n, ras_n, we_n), (1, 1, 1)) dut = SteererDUT(nranks=2, dfi_databits=16, nphases=2) run_simulation(dut, main_generator(dut)) def test_connect_only_if_valid_and_ready(self): # Commands should be connected to phases only if they are valid & ready. def main_generator(dut): # Set possible requests yield from dut.drivers[STEER_NOP].nop() yield from dut.drivers[STEER_CMD].activate() yield from dut.drivers[STEER_REQ].write() yield from dut.drivers[STEER_REFRESH].refresh() # Set how phases are steered yield dut.steerer.sel[0].eq(STEER_CMD) yield dut.steerer.sel[1].eq(STEER_NOP) yield yield def check(is_ready): # CMD on phase 0 should be STEER_CMD=activate p = dut.dfi.phases[0] self.assertEqual((yield p.bank), STEER_CMD) self.assertEqual((yield p.address), STEER_CMD) if is_ready: self.assertEqual((yield p.cas_n), 1) self.assertEqual((yield p.ras_n), 0) self.assertEqual((yield p.we_n), 1) else: # Not steered self.assertEqual((yield p.cas_n), 1) self.assertEqual((yield p.ras_n), 1) self.assertEqual((yield p.we_n), 1) # Nop on phase 1 should be STEER_NOP p = dut.dfi.phases[1] self.assertEqual((yield p.cas_n), 1) self.assertEqual((yield p.ras_n), 1) self.assertEqual((yield p.we_n), 1) yield from check(is_ready=False) yield dut.commands[STEER_CMD].ready.eq(1) yield yield yield from check(is_ready=True) dut = SteererDUT(nranks=2, dfi_databits=16, nphases=2) run_simulation(dut, main_generator(dut)) def test_no_decode_ba_signle_rank(self): # With a single rank the whole `ba` signal is bank address. def main_generator(dut): yield from dut.drivers[STEER_NOP].nop() yield from dut.drivers[STEER_REQ].write() yield from dut.drivers[STEER_REFRESH].refresh() # All the bits are for bank dut.drivers[STEER_CMD].bank = 0b110 yield from dut.drivers[STEER_CMD].activate() yield dut.commands[STEER_CMD].ready.eq(1) # Set how phases are steered yield dut.steerer.sel[0].eq(STEER_NOP) yield dut.steerer.sel[1].eq(STEER_CMD) yield yield p = dut.dfi.phases[1] self.assertEqual((yield p.cas_n), 1) self.assertEqual((yield p.ras_n), 0) self.assertEqual((yield p.we_n), 1) self.assertEqual((yield p.address), STEER_CMD) self.assertEqual((yield p.bank), 0b110) self.assertEqual((yield p.cs_n), 0) dut = SteererDUT(nranks=1, dfi_databits=16, nphases=2) run_simulation(dut, main_generator(dut)) def test_decode_ba_multiple_ranks(self): # With multiple ranks `ba` signal should be split into bank and chip select. def main_generator(dut): yield from dut.drivers[STEER_NOP].nop() yield from dut.drivers[STEER_REQ].write() yield from dut.drivers[STEER_REFRESH].refresh() # Set how phases are steered yield dut.steerer.sel[0].eq(STEER_NOP) yield dut.steerer.sel[1].eq(STEER_CMD) variants = [ # ba, phase.bank, phase.cs_n (0b110, 0b10, 0b01), # rank=1 -> cs=0b10 -> cs_n=0b01 (0b101, 0b01, 0b01), # rank=1 -> cs=0b10 -> cs_n=0b01 (0b001, 0b01, 0b10), # rank=0 -> cs=0b01 -> cs_n=0b10 ] for ba, phase_bank, phase_cs_n in variants: with self.subTest(ba=ba): # 1 bit for rank, 2 bits for bank dut.drivers[STEER_CMD].bank = ba yield from dut.drivers[STEER_CMD].activate() yield dut.commands[STEER_CMD].ready.eq(1) yield yield p = dut.dfi.phases[1] self.assertEqual((yield p.cas_n), 1) self.assertEqual((yield p.ras_n), 0) self.assertEqual((yield p.we_n), 1) self.assertEqual((yield p.bank), phase_bank) self.assertEqual((yield p.cs_n), phase_cs_n) dut = SteererDUT(nranks=2, dfi_databits=16, nphases=2) run_simulation(dut, main_generator(dut)) def test_select_all_ranks_on_refresh(self): # When refresh command is on first phase, all ranks should be selected. def main_generator(dut): yield from dut.drivers[STEER_NOP].nop() yield from dut.drivers[STEER_REQ].write() yield from dut.drivers[STEER_CMD].activate() # Set how phases are steered yield dut.steerer.sel[0].eq(STEER_REFRESH) yield dut.steerer.sel[1].eq(STEER_NOP) variants = [ # ba, phase.bank, phase.cs_n (always all enabled) (0b110, 0b10, 0b00), (0b101, 0b01, 0b00), (0b001, 0b01, 0b00), ] for ba, phase_bank, phase_cs_n in variants: with self.subTest(ba=ba): # 1 bit for rank, 2 bits for bank dut.drivers[STEER_REFRESH].bank = ba yield from dut.drivers[STEER_REFRESH].refresh() yield dut.commands[STEER_REFRESH].ready.eq(1) yield yield p = dut.dfi.phases[0] self.assertEqual((yield p.cas_n), 0) self.assertEqual((yield p.ras_n), 0) self.assertEqual((yield p.we_n), 1) self.assertEqual((yield p.bank), phase_bank) self.assertEqual((yield p.cs_n), phase_cs_n) dut = SteererDUT(nranks=2, dfi_databits=16, nphases=2) run_simulation(dut, main_generator(dut)) def test_reset_n_high(self): # Reset_n should be 1 for all phases at all times. def main_generator(dut): yield dut.steerer.sel[0].eq(STEER_CMD) yield dut.steerer.sel[1].eq(STEER_NOP) yield self.assertEqual((yield dut.dfi.phases[0].reset_n), 1) self.assertEqual((yield dut.dfi.phases[1].reset_n), 1) self.assertEqual((yield dut.dfi.phases[2].reset_n), 1) self.assertEqual((yield dut.dfi.phases[3].reset_n), 1) dut = SteererDUT(nranks=2, dfi_databits=16, nphases=4) run_simulation(dut, main_generator(dut)) def test_cke_high_all_ranks(self): # CKE should be 1 for all phases and ranks at all times. def main_generator(dut): yield dut.steerer.sel[0].eq(STEER_CMD) yield dut.steerer.sel[1].eq(STEER_NOP) yield self.assertEqual((yield dut.dfi.phases[0].cke), 0b11) self.assertEqual((yield dut.dfi.phases[1].cke), 0b11) self.assertEqual((yield dut.dfi.phases[2].cke), 0b11) self.assertEqual((yield dut.dfi.phases[3].cke), 0b11) dut = SteererDUT(nranks=2, dfi_databits=16, nphases=4) run_simulation(dut, main_generator(dut)) def test_odt_high_all_ranks(self): # ODT should be 1 for all phases and ranks at all times. # NOTE: only until dynamic ODT is implemented. def main_generator(dut): yield dut.steerer.sel[0].eq(STEER_CMD) yield dut.steerer.sel[1].eq(STEER_NOP) yield self.assertEqual((yield dut.dfi.phases[0].odt), 0b11) self.assertEqual((yield dut.dfi.phases[1].odt), 0b11) self.assertEqual((yield dut.dfi.phases[2].odt), 0b11) self.assertEqual((yield dut.dfi.phases[3].odt), 0b11) dut = SteererDUT(nranks=2, dfi_databits=16, nphases=4) run_simulation(dut, main_generator(dut))