#
# This file is part of LiteX-Boards.
#
# Copyright (c) 2018 William D. Jones <thor0505@comcast.net>
# Copyright (c) 2020 Staf Verhaegen <staf@fibraservi.eu>
# Copyright (c) 2021 Michael T. Mayers <michael@tweakoz.com>
# SPDX-License-Identifier: BSD-2-Clause

from litex.build.generic_platform import Pins, Subsignal, IOStandard, Misc
from litex.build.xilinx import XilinxPlatform
from litex.build.openocd import OpenOCD

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

_io = [
    # Clk / Rst
    ("clk50", 0, Pins("N14"), IOStandard("LVCMOS33")),

    # Leds
    ("user_led", 0, Pins("M1"),  IOStandard("LVCMOS33")),
    ("user_led", 1, Pins("A14"), IOStandard("LVCMOS33")),
    ("user_led", 2, Pins("A13"), IOStandard("LVCMOS33")),

    # Serial
    ("serial", 0,
        Subsignal("tx", Pins("N11")), # BDBUS1
        Subsignal("rx", Pins("E11")), # BDBUS0
        IOStandard("LVCMOS33")
    ),

    # SRAM
    ("issiram", 0,
        Subsignal("addr", Pins(
            "M4 N3 N4 P3 M5 E5 D5 D3",
            "B7 B4 J4 H4 H3 G4 E6 A7",
            "A5 A4 C4"),
            IOStandard("LVCMOS33")),
        Subsignal("data", Pins(
            "L5 L3 L4 R2 F3 F4 E3 D6"),
            IOStandard("LVCMOS33")),
        Subsignal("wen", Pins("R1"), IOStandard("LVCMOS33")),
        Subsignal("cen", Pins("M6"), IOStandard("LVCMOS33")),
        Misc("SLEW=FAST"),
    ),
]

# Connectors ---------------------------------------------------------------------------------------

_connectors = []

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

class Platform(XilinxPlatform):
    default_clk_name   = "clk50"
    default_clk_period = 1e9/50e6

    def __init__(self, toolchain="vivado"):
        XilinxPlatform.__init__(self, "xc7a35tftg256-1", _io, _connectors, toolchain=toolchain)

    def do_finalize(self,fragment):
        XilinxPlatform.do_finalize(self, fragment)
        self.add_period_constraint(self.lookup_request("clk50", loose=True), self.default_clk_period)