#!/usr/bin/env python3 # # This file is part of LiteX-Boards. # # Copyright (c) 2019 Sean Cross # Copyright (c) 2018 David Shah # Copyright (c) 2020 Piotr Esden-Tempski # Copyright (c) 2020 Florent Kermarrec # 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): mem_map = {**SoCCore.mem_map, **{"spiflash": 0x80000000}} 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 # Set CPU variant / reset address kwargs["cpu_reset_address"] = self.mem_map["spiflash"] + bios_flash_offset # SoCCore ---------------------------------------------------------------------------------- SoCCore.__init__(self, platform, sys_clk_freq, ident = "LiteX SoC on iCEBreaker", ident_version = True, **kwargs) # CRG -------------------------------------------------------------------------------------- self.submodules.crg = _CRG(platform, sys_clk_freq) # 128KB SPRAM (used as SRAM) --------------------------------------------------------------- self.submodules.spram = Up5kSPRAM(size=128*kB) self.bus.add_slave("sram", self.spram.bus, SoCRegion(size=128*kB)) # 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) #self.add_spi_flash(mode="1x", dummy_cycles=8) # LiteX SPI Flash Core. # Add ROM linker region -------------------------------------------------------------------- self.bus.add_region("rom", SoCRegion( origin = self.mem_map["spiflash"] + bios_flash_offset, size = 32*kB, linker = True) ) # 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") parser.add_argument("--sys-clk-freq", default=24e6, help="System clock frequency (default: 24MHz)") parser.add_argument("--bios-flash-offset", default=0x40000, help="BIOS offset in SPI Flash (default: 0x40000)") 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 = args.bios_flash_offset, 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()