litex-boards/litex_boards/targets/1bitsquared_icebreaker.py

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#!/usr/bin/env python3
#
# This file is part of LiteX-Boards.
#
# Copyright (c) 2019 Sean Cross <sean@xobs.io>
# Copyright (c) 2018 David Shah <dave@ds0.me>
# Copyright (c) 2020 Piotr Esden-Tempski <piotr@esden.net>
# Copyright (c) 2020 Florent Kermarrec <florent@enjoy-digital.fr>
# SPDX-License-Identifier: BSD-2-Clause
# The iCEBreaker is the first open source iCE40 FPGA development board designed for teachers and
# students: https://www.crowdsupply.com/1bitsquared/icebreaker-fpga
# This target file provides a minimal LiteX SoC for the iCEBreaker with a CPU, its ROM (in SPI Flash),
# its SRAM, close to the others LiteX targets. A more complete example of LiteX SoC for the iCEBreaker
# with more features, examples to run C/Rust code on the RISC-V CPU and documentation can be found
# at: https://github.com/icebreaker-fpga/icebreaker-litex-examples
import os
import argparse
from migen import *
from migen.genlib.resetsync import AsyncResetSynchronizer
from litex_boards.platforms import icebreaker
from litex.soc.cores.ram import Up5kSPRAM
from litex.soc.cores.clock import iCE40PLL
from litex.soc.integration.soc_core import *
from litex.soc.integration.soc import SoCRegion
from litex.soc.integration.builder import *
from litex.soc.cores.video import VideoDVIPHY
from litex.soc.cores.led import LedChaser
kB = 1024
mB = 1024*kB
# CRG ----------------------------------------------------------------------------------------------
class _CRG(Module):
def __init__(self, platform, sys_clk_freq):
self.rst = Signal()
self.clock_domains.cd_sys = ClockDomain()
self.clock_domains.cd_por = ClockDomain(reset_less=True)
# # #
# Clk/Rst
clk12 = platform.request("clk12")
rst_n = platform.request("user_btn_n")
# Power On Reset
por_count = Signal(16, reset=2**16-1)
por_done = Signal()
self.comb += self.cd_por.clk.eq(ClockSignal())
self.comb += por_done.eq(por_count == 0)
self.sync.por += If(~por_done, por_count.eq(por_count - 1))
# PLL
self.submodules.pll = pll = iCE40PLL(primitive="SB_PLL40_PAD")
self.comb += pll.reset.eq(~rst_n) # FIXME: Add proper iCE40PLL reset support and add back | self.rst.
pll.register_clkin(clk12, 12e6)
pll.create_clkout(self.cd_sys, sys_clk_freq, with_reset=False)
self.specials += AsyncResetSynchronizer(self.cd_sys, ~por_done | ~pll.locked)
platform.add_period_constraint(self.cd_sys.clk, 1e9/sys_clk_freq)
# BaseSoC ------------------------------------------------------------------------------------------
class BaseSoC(SoCCore):
def __init__(self, bios_flash_offset, sys_clk_freq=int(24e6), with_led_chaser=True,
with_video_terminal=False, **kwargs):
platform = icebreaker.Platform()
platform.add_extension(icebreaker.break_off_pmod)
# Disable Integrated ROM/SRAM since too large for iCE40 and UP5K has specific SPRAM.
kwargs["integrated_sram_size"] = 0
kwargs["integrated_rom_size"] = 0
# SoCCore ----------------------------------------------------------------------------------
SoCCore.__init__(self, platform, sys_clk_freq,
ident = "LiteX SoC on iCEBreaker",
**kwargs)
# CRG --------------------------------------------------------------------------------------
self.submodules.crg = _CRG(platform, sys_clk_freq)
# 128KB SPRAM (used as 64kB SRAM / 64kB RAM) -----------------------------------------------
self.submodules.spram = Up5kSPRAM(size=128*kB)
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self.bus.add_slave("psram", self.spram.bus, SoCRegion(size=128*kB))
self.bus.add_region("sram", SoCRegion(
origin = self.bus.regions["psram"].origin + 0*kB,
size = 64*kB,
linker = True)
)
if not self.integrated_main_ram_size:
self.bus.add_region("main_ram", SoCRegion(
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origin = self.bus.regions["psram"].origin + 64*kB,
size = 64*kB,
linker = True)
)
# SPI Flash --------------------------------------------------------------------------------
from litespi.modules import W25Q128JV
from litespi.opcodes import SpiNorFlashOpCodes as Codes
self.add_spi_flash(mode="4x", module=W25Q128JV(Codes.READ_1_1_4), with_master=False)
# Add ROM linker region --------------------------------------------------------------------
self.bus.add_region("rom", SoCRegion(
origin = self.bus.regions["spiflash"].origin + bios_flash_offset,
size = 32*kB,
linker = True)
)
self.cpu.set_reset_address(self.bus.regions["rom"].origin)
# Video ------------------------------------------------------------------------------------
if with_video_terminal:
platform.add_extension(icebreaker.dvi_pmod)
self.submodules.videophy = VideoDVIPHY(platform.request("dvi"), clock_domain="sys")
self.add_video_terminal(phy=self.videophy, timings="640x480@75Hz", clock_domain="sys")
# Leds -------------------------------------------------------------------------------------
if with_led_chaser:
self.submodules.leds = LedChaser(
pads = platform.request_all("user_led"),
sys_clk_freq = sys_clk_freq)
# Flash --------------------------------------------------------------------------------------------
def flash(build_dir, build_name, bios_flash_offset):
from litex.build.lattice.programmer import IceStormProgrammer
prog = IceStormProgrammer()
prog.flash(bios_flash_offset, f"{build_dir}/software/bios/bios.bin")
prog.flash(0x00000000, f"{build_dir}/gateware/{build_name}.bin")
# Build --------------------------------------------------------------------------------------------
def main():
parser = argparse.ArgumentParser(description="LiteX SoC on iCEBreaker")
parser.add_argument("--build", action="store_true", help="Build bitstream.")
parser.add_argument("--load", action="store_true", help="Load bitstream.")
parser.add_argument("--flash", action="store_true", help="Flash Bitstream and BIOS.")
parser.add_argument("--sys-clk-freq", default=24e6, help="System clock frequency.")
parser.add_argument("--bios-flash-offset", default="0x40000", help="BIOS offset in SPI Flash.")
parser.add_argument("--with-video-terminal", action="store_true", help="Enable Video Terminal (with DVI PMOD).")
builder_args(parser)
soc_core_args(parser)
args = parser.parse_args()
soc = BaseSoC(
bios_flash_offset = int(args.bios_flash_offset, 0),
sys_clk_freq = int(float(args.sys_clk_freq)),
with_video_terminal = args.with_video_terminal,
**soc_core_argdict(args)
)
builder = Builder(soc, **builder_argdict(args))
builder.build(run=args.build)
if args.load:
prog = soc.platform.create_programmer()
prog.load_bitstream(os.path.join(builder.gateware_dir, soc.build_name + ".bin"))
if args.flash:
flash(builder.output_dir, soc.build_name, args.bios_flash_offset)
if __name__ == "__main__":
main()