usb3_pipe/pcie_screamer.py

# This file is Copyright (c) 2019 Florent Kermarrec <florent@enjoy-digital.fr>
# License: BSD

#!/usr/bin/env python3

from migen import *

from litex.build.generic_platform import *
from litex.build.xilinx import XilinxPlatform

from litex.soc.cores.clock import *
from litex.soc.interconnect.csr import *
from litex.soc.integration.soc_core import *
from litex.soc.integration.builder import *
from litex.soc.cores.uart import UARTWishboneBridge


from litescope import LiteScopeAnalyzer

from usb3_pipe.serdes import A7USB3SerDes
from usb3_pipe.lfps import LFPSUnit
from usb3_pipe.ordered_set import OrderedSetUnit
from usb3_pipe.ltssm import LTSSM

# IOs ----------------------------------------------------------------------------------------------

_io = [
    ("clk100", 0, Pins("R4"), IOStandard("LVCMOS33")),

    ("user_led", 0, Pins("AB1"), IOStandard("LVCMOS33")),
    ("user_led", 1, Pins("AB8"), IOStandard("LVCMOS33")),

    ("user_btn", 0, Pins("AA1"), IOStandard("LVCMOS33")),
    ("user_btn", 1, Pins("AB6"), IOStandard("LVCMOS33")),

    ("serial", 0,
        Subsignal("tx", Pins("T1")),
        Subsignal("rx", Pins("U1")),
        IOStandard("LVCMOS33"),
    ),

    ("pcie_tx", 0,
        Subsignal("p", Pins("B6")),
        Subsignal("n", Pins("A6")),
    ),

    ("pcie_rx", 0,
        Subsignal("p", Pins("B10")),
        Subsignal("n", Pins("A10")),
    ),
]

# Platform -----------------------------------------------------------------------------------------

class Platform(XilinxPlatform):
    def __init__(self):
        XilinxPlatform.__init__(self, "xc7a35t-fgg484-2", _io, toolchain="vivado")

# CRG ----------------------------------------------------------------------------------------------

class _CRG(Module):
    def __init__(self, platform, sys_clk_freq):
        self.clock_domains.cd_sys = ClockDomain()
        self.clock_domains.cd_oob = ClockDomain()
        self.clock_domains.cd_clk125 = ClockDomain()

        # # #

        clk100 = platform.request("clk100")
        platform.add_period_constraint(clk100, 1e9/100e6)

        self.cd_sys.clk.attr.add("keep")
        self.cd_clk125.clk.attr.add("keep")

        self.submodules.pll = pll = S7PLL(speedgrade=-2)
        pll.register_clkin(clk100, 100e6)
        pll.create_clkout(self.cd_sys, sys_clk_freq)
        pll.create_clkout(self.cd_oob, sys_clk_freq/8)
        pll.create_clkout(self.cd_clk125, 125e6)

# USB3SoC ------------------------------------------------------------------------------------------

class USB3SoC(SoCMini):
    def __init__(self, platform,
        with_analyzer=False):

        sys_clk_freq = int(100e6)
        SoCMini.__init__(self, platform, sys_clk_freq, ident="USB3SoC", ident_version=True)

        # CRG --------------------------------------------------------------------------------------
        self.submodules.crg = _CRG(platform, sys_clk_freq)

        # Serial bridge ----------------------------------------------------------------------------
        self.submodules.serial_bridge = UARTWishboneBridge(platform.request("serial"), sys_clk_freq)
        self.add_wb_master(self.serial_bridge.wishbone)

        # SerDes -----------------------------------------------------------------------------------
        serdes = A7USB3SerDes(platform,
            sys_clk      = self.crg.cd_sys.clk,
            sys_clk_freq = sys_clk_freq,
            refclk_pads  = ClockSignal("clk125"),
            refclk_freq  = 125e6,
            tx_pads      = platform.request("pcie_tx"),
            rx_pads      = platform.request("pcie_rx"))
        self.submodules += serdes

        # LFPS Unit --------------------------------------------------------------------------------
        lfps_unit = LFPSUnit(sys_clk_freq=sys_clk_freq, serdes=serdes)
        self.submodules += lfps_unit

        # OrderedSet Unit --------------------------------------------------------------------------
        ordered_set_unit = OrderedSetUnit(serdes=serdes)
        self.submodules += ordered_set_unit

        # LTSSM ------------------------------------------------------------------------------------
        ltssm = LTSSM(lfps_unit=lfps_unit, ordered_set_unit=ordered_set_unit)
        self.submodules += ltssm

        # Leds -------------------------------------------------------------------------------------
        self.comb += platform.request("user_led", 0).eq(serdes.ready)
        self.comb += platform.request("user_led", 1).eq(ltssm.polling_fsm.idle)

        # Analyzer ---------------------------------------------------------------------------------
        if with_analyzer:
            analyzer_signals = [
                ltssm.polling_fsm,
                serdes.source,
                serdes.sink,
            ]
            self.submodules.analyzer = LiteScopeAnalyzer(analyzer_signals, 4096, csr_csv="tools/analyzer.csv")
            self.add_csr("analyzer")

# Build --------------------------------------------------------------------------------------------

def main():
    platform = Platform()
    soc = USB3SoC(platform)
    builder = Builder(soc, output_dir="build", csr_csv="tools/csr.csv")
    vns = builder.build()

if __name__ == "__main__":
    main()