#!/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 from migen import * from migen.genlib.resetsync import AsyncResetSynchronizer from litex.gen import * 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 # CRG ---------------------------------------------------------------------------------------------- class _CRG(LiteXModule): def __init__(self, platform, sys_clk_freq): self.rst = Signal() self.cd_sys = ClockDomain() self.cd_por = ClockDomain() # # # # 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.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=24e6, with_led_chaser = True, with_video_terminal = False, **kwargs): platform = icebreaker.Platform() platform.add_extension(icebreaker.break_off_pmod) # CRG -------------------------------------------------------------------------------------- self.crg = _CRG(platform, sys_clk_freq) # SoCCore ---------------------------------------------------------------------------------- # 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.__init__(self, platform, sys_clk_freq, ident="LiteX SoC on iCEBreaker", **kwargs) # 128KB SPRAM (used as 64kB SRAM / 64kB RAM) ----------------------------------------------- self.spram = Up5kSPRAM(size=128 * KILOBYTE) self.bus.add_slave("psram", self.spram.bus, SoCRegion(origin=self.mem_map["sram"], size=128 * KILOBYTE)) self.bus.add_region("sram", SoCRegion( origin = self.bus.regions["psram"].origin + 0 * KILOBYTE, size = 64 * KILOBYTE, linker = True) ) if not self.integrated_main_ram_size: self.bus.add_region("main_ram", SoCRegion( origin = self.bus.regions["psram"].origin + 64 * KILOBYTE, size = 64 * KILOBYTE, 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 * KILOBYTE, linker = True) ) self.cpu.set_reset_address(self.bus.regions["rom"].origin) # Video ------------------------------------------------------------------------------------ if with_video_terminal: platform.add_extension(icebreaker.dvi_pmod) self.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.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(): from litex.build.parser import LiteXArgumentParser parser = LiteXArgumentParser(platform=icebreaker.Platform, description="LiteX SoC on iCEBreaker.") parser.add_target_argument("--flash", action="store_true", help="Flash Bitstream and BIOS.") parser.add_target_argument("--sys-clk-freq", default=24e6, type=float, help="System clock frequency.") parser.add_target_argument("--bios-flash-offset", default="0x40000", help="BIOS offset in SPI Flash.") parser.add_target_argument("--with-video-terminal", action="store_true", help="Enable Video Terminal (with DVI PMOD).") args = parser.parse_args() soc = BaseSoC( bios_flash_offset = int(args.bios_flash_offset, 0), sys_clk_freq = args.sys_clk_freq, with_video_terminal = args.with_video_terminal, **parser.soc_argdict ) builder = Builder(soc, **parser.builder_argdict) if args.build: builder.build(**parser.toolchain_argdict) if args.load: prog = soc.platform.create_programmer() prog.load_bitstream(builder.get_bitstream_filename(mode="sram", ext=".bin")) # FIXME if args.flash: flash(builder.output_dir, soc.build_name, args.bios_flash_offset) if __name__ == "__main__": main()