From c795bafda7ba57d4cba40db898c92d519faa9c59 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C4=99drzej=20Boczar?= Date: Wed, 14 Jul 2021 14:00:42 +0200 Subject: [PATCH] phy/lpddr5/sim: add verification of initialization sequence --- litedram/phy/lpddr5/sim.py | 144 ++++++++++++++++++++++++++++++++-- litedram/phy/lpddr5/simsoc.py | 1 + 2 files changed, 138 insertions(+), 7 deletions(-) diff --git a/litedram/phy/lpddr5/sim.py b/litedram/phy/lpddr5/sim.py index 4056046..80b95be 100644 --- a/litedram/phy/lpddr5/sim.py +++ b/litedram/phy/lpddr5/sim.py @@ -4,6 +4,7 @@ # Copyright (c) 2021 Antmicro # SPDX-License-Identifier: BSD-2-Clause +import math from operator import or_ from functools import reduce from collections import OrderedDict @@ -15,7 +16,7 @@ from litex.soc.interconnect.csr import AutoCSR # from litedram.common import TappedDelayLine from litedram.phy.utils import edge, delayed -from litedram.phy.sim_utils import SimLogger, PulseTiming, log_level_getter +from litedram.phy.sim_utils import SimLogger, Timing, PulseTiming, log_level_getter CMD_INFO_LAYOUT = [ @@ -32,7 +33,7 @@ gtkw_dbg = {} class LPDDR5Sim(Module, AutoCSR): """LPDDR5 DRAM simulation """ - def __init__(self, pads, *, log_level, logger_kwargs): + def __init__(self, pads, *, ck_freq, log_level, logger_kwargs): log_level = log_level_getter(log_level) self.clock_domains.cd_ck = ClockDomain(reset_less=True) @@ -53,7 +54,7 @@ class LPDDR5Sim(Module, AutoCSR): cmd_info = stream.Endpoint(CMD_INFO_LAYOUT) gtkw_dbg["cmd_info"] = cmd_info - cmd = CommandsSim(pads, cmd_info, logger_kwargs=logger_kwargs, log_level=log_level) + cmd = CommandsSim(pads, cmd_info, ck_freq=ck_freq, logger_kwargs=logger_kwargs, log_level=log_level) self.submodules.cmd = ClockDomainsRenamer("ck")(cmd) data = DataSim(pads, cmd_info, cmd.data_timer.ready_p, logger_kwargs=logger_kwargs, log_level=log_level) @@ -224,7 +225,7 @@ class Sync(list): class CommandsSim(Module, AutoCSR): - def __init__(self, pads, cmd_info, *, log_level, logger_kwargs): + def __init__(self, pads, cmd_info, *, ck_freq, log_level, logger_kwargs): self.submodules.log = SimLogger(log_level=log_level("cmd"), **logger_kwargs) self.comb += self.log.info("Simulation start") @@ -235,6 +236,13 @@ class CommandsSim(Module, AutoCSR): self.active_banks = Array([Signal(name=f"bank{i}_active") for i in range(self.nbanks)]) self.active_rows = Array([Signal(18, name=f"bank{i}_active_row") for i in range(self.nbanks)]) + # MPC operand + self.mpc_op = Signal(8) + + # ZQ calibration TODO: implement ZQC logic + self.zqc_start = Signal() + self.zqc_latch = Signal() + # The captured command is delayed and the timer starts 1 cycle later: # CK --____----____----____----____----____-- # CS __--------______________________________ (center-aligned to CK) @@ -281,11 +289,12 @@ class CommandsSim(Module, AutoCSR): MRW = self.mrw_handler(), DATA = self.data_handler(), CAS = self.cas_handler(), + MPC = self.mpc_handler(), + # MRR # WRITE/MASKED-WRITE # READ # CAS # MPC - # MRR # WFF/RFF? # RDC? ) @@ -294,10 +303,116 @@ class CommandsSim(Module, AutoCSR): If(self.handle_cmd & ~reduce(or_, cmd_handlers.values()), self.log.error("Unexpected command: CA_p=0b%07b CA_n=0b%07b", self.ca_p, self.ca_n) ), - - cmds_enabled.eq(1), + If(cs & ~cmds_enabled, + self.log.warn("Received command when no commands should be sent: CA_p=0b%07b CA_n=0b%07b", self.ca_p, self.ca_n) + ), ] + ck = lambda t: math.ceil(t * ck_freq) + ms, us, ns = 1e-3, 1e-6, 1e-9 + self.submodules.tinit0 = PulseTiming(ck(20*ms)) # (max) voltage-ramp at power-up; not applicable in the simulation + self.submodules.tinit1 = PulseTiming(ck(200*us)) # (min) reset_n low time after voltage-ramp completion + self.submodules.tinit2 = Timing(ck(10*ns)) # (min) CS low time before reset deassertion + self.submodules.tinit3 = PulseTiming(ck(2*ms)) # (min) CS low time after reset deassertion + self.submodules.tinit4 = PulseTiming(5) # (min) stabilized CK before CS high; not really applicable in this simulation + self.submodules.tinit5 = PulseTiming(ck(2*us)) # (min) idle time before first MRW/MRR cmmand + self.submodules.tzqlat = PulseTiming(max(4, ck(30*ns))) # (min) ZQCAL latch quiet time + + self.comb += [ + If(edge(self, pads.reset_n), + self.log.info("RESET released"), + ).Elif(edge(self, ~pads.reset_n), + self.log.info("RESET asserted"), + ), + ] + + # NOTE: for simulation purpose we assume that CK is always running because CommandsSim is clocked + # from it, or else the states up to Tc would make no sense because the timings would not be counted + self.submodules.fsm = fsm = FSM() + fsm.act("RESET", + self.tinit1.trigger.eq(1), + self.tinit2.valid.eq(~pads.cs), + If(edge(self, pads.reset_n), + If(~self.tinit1.ready, + self.log.warn("tINIT1 violated: RESET deasserted too fast") + ), + If(~self.tinit2.ready, + self.log.warn("tINIT2 violated: CS LOW for too short before deasserting RESET") + ), + NextState("WAIT-NOP") # Tc + ), + ) + fsm.act("WAIT-NOP", + self.tinit3.trigger.eq(1), + If(cs & ~self.tinit3.ready, + self.log.warn("tINIT3 violated: CS high too fast after RESET deassertion") + ), + self.tinit4.trigger.eq(1), + If(cs & ~self.tinit4.ready, + self.log.warn("tINIT4 violated: CS high too fast after stable CK") + ), + If(cs, + self.tinit5.trigger.eq(1), + If(~self.tinit4.ready, + self.log.warn("tINIT4 violated: CS HIGH too fast while waiting for initial NOP") + ), + If((self.ca_p != 0) | (self.ca_n != 0), + self.log.warn("Waiting for NOP but got CA_p=0b%07b CA_n=0b%07b", self.ca_p, self.ca_n) + ), + NextState("NO-CMDS"), # Te + ) + ) + fsm.act("NO-CMDS", + self.tinit5.trigger.eq(1), + If(cs, + self.log.warn("tINIT5 violated: command issued too fast after initial NOP") + ), + If(self.tinit5.ready, + NextState("MODE-REGS") # Tf + ) + ) + fsm.act("MODE-REGS", + cmds_enabled.eq(1), + # If(self.handle_cmd & ~cmd_handlers["MRW"] & ~cmd_handlers["MRR"] & ~cmd_handlers["MPC"], # TODO: MRR + If(self.handle_cmd & ~cmd_handlers["MRW"] & ~cmd_handlers["MPC"], + self.log.warn("Only MRW/MRR commands expected before ZQ Latch ..."), + self.log.warn("... " + " ".join("{}=%d".format(cmd) for cmd in cmd_handlers.keys()), *cmd_handlers.values()), + ), + If(cmd_handlers["MPC"], + If(~self.zqc_latch, + self.log.error("ZQC-LATCH expected, got MPC with op=0b%07b", self.mpc_op) + ).Else( + NextState("ZQC-LATCH") # Tg + ) + ), + ) + fsm.act("ZQC-LATCH", + cmds_enabled.eq(1), + self.tzqlat.trigger.eq(1), + If(self.handle_cmd, + self.log.error("tZQCAL violated: new command issued too fast: CA_p=0b%07b CA_n=0b%07b", self.ca_p, self.ca_n) + ), + If(self.tzqlat.ready, + NextState("NORMAL"), # Th + ) + ) + fsm.act("NORMAL", + cmds_enabled.eq(1) + ) + + # Log state transitions + fsm.finalize() + prev_state = delayed(self, fsm.state) + self.comb += If(prev_state != fsm.state, + Case(prev_state, { + state: Case(fsm.state, { + next_state: self.log.info(f"FSM: {state_name} -> {next_state_name}") + for next_state, next_state_name in fsm.decoding.items() + }) + for state, state_name in fsm.decoding.items() + }) + ) + def activate_handler(self): bank = Signal(max=self.nbanks) row1 = Signal(4) @@ -384,6 +499,21 @@ class CommandsSim(Module, AutoCSR): ] ) + def mpc_handler(self): + op = Signal(8) + return self.cmd_one_step("MRW", + cond = self.ca_p[:6] == 0b110000, + body = [ + op.eq(Cat(self.ca_n, self.ca_p[6])), + self.mpc_op.eq(op), + self.zqc_start.eq(op == 0b10000101), + self.zqc_latch.eq(op == 0b10000110), + If(~(self.zqc_start | self.zqc_latch), + self.log.warn("Unsupported MPC command: op=0b%08b", op), + ), + ], + ) + def cas_handler(self): ws_wr = Signal() ws_rd = Signal() diff --git a/litedram/phy/lpddr5/simsoc.py b/litedram/phy/lpddr5/simsoc.py index ff32af5..b568985 100644 --- a/litedram/phy/lpddr5/simsoc.py +++ b/litedram/phy/lpddr5/simsoc.py @@ -139,6 +139,7 @@ class SimSoC(SoCCore): # LPDDR5 Sim ------------------------------------------------------------------------------- self.submodules.lpddr5sim = LPDDR5Sim( pads = self.ddrphy.pads, + ck_freq = sys_clk_freq, log_level = log_level, logger_kwargs = dict( clk_freq_cd = f"sys{2*wck_ck_ratio}x",