#!/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 # Copyright (c) 2021 Sylvain Munaut # SPDX-License-Identifier: BSD-2-Clause # This target file provides a minimal LiteX SoC for the iCEBreaker-bitsy with a CPU, # its ROM (in SPI Flash), its SRAM, close to the others LiteX targets. # For more complete example of LiteX SoC for the iCEBreaker-bitsy with more features and # documentation can be found, refer to : # 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_bitsy 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.led import LedChaser kB = 1024 mB = 1024*kB # CRG ---------------------------------------------------------------------------------------------- class _CRG(LiteXModule): def __init__(self, platform, sys_clk_freq=48e6, with_usb_pll=False): assert not with_usb_pll or sys_clk_freq == 48e6 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 if with_usb_pll: self.cd_usb_12 = ClockDomain() self.cd_usb_48 = ClockDomain() locked = Signal() self.specials.pll = pll = Instance("SB_PLL40_2F_PAD", i_PACKAGEPIN = clk12, i_RESETB = rst_n, i_BYPASS = C(0), # o_PLLOUTGLOBALA = self.cd_sys.clk, o_PLLOUTGLOBALA = self.cd_usb_48.clk, o_PLLOUTGLOBALB = self.cd_usb_12.clk, o_LOCK = locked, # Create a 48 MHz PLL clock... p_FEEDBACK_PATH = "SIMPLE", p_PLLOUT_SELECT_PORTA = "GENCLK", p_PLLOUT_SELECT_PORTB = "SHIFTREG_0deg", p_DIVR = 0, p_DIVF = 63, p_DIVQ = 4, p_FILTER_RANGE = 1, ) self.specials += AsyncResetSynchronizer(self.cd_sys, ~por_done | ~locked) platform.add_period_constraint(self.cd_sys.clk, 48e6) platform.add_period_constraint(self.cd_usb_48.clk, 48e6) platform.add_period_constraint(self.cd_usb_12.clk, 12e6) self.comb += [ self.cd_sys.clk.eq(self.cd_usb_48.clk), ] else: 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, revision="v1", with_led_chaser=True, **kwargs): platform = icebreaker_bitsy.Platform(revision=revision) # CRG -------------------------------------------------------------------------------------- with_usb_acm = kwargs["uart_name"] == "usb_acm" if with_usb_acm: sys_clk_freq = 48e6 self.crg = _CRG(platform, sys_clk_freq, with_usb_pll=with_usb_acm) # 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-bitsy", **kwargs) # 128KB SPRAM (used as 64kB SRAM / 64kB RAM) ----------------------------------------------- self.spram = Up5kSPRAM(size=128*kB) 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( origin = self.bus.regions["psram"].origin + 64*kB, size = 64*kB, linker = True) ) # LED Chaser -------------------------------------------------------------------------------- if with_led_chaser: self.leds = LedChaser( pads = platform.request_all("user_led_n"), sys_clk_freq = sys_clk_freq, polarity = 1) # 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) # Build -------------------------------------------------------------------------------------------- def main(): from litex.build.parser import LiteXArgumentParser parser = LiteXArgumentParser(platform=icebreaker_bitsy.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="0xa0000", help="BIOS offset in SPI Flash.") parser.add_target_argument("--revision", default="v1", help="Board revision (v0 or v1).") args = parser.parse_args() soc = BaseSoC( bios_flash_offset = int(args.bios_flash_offset, 0), sys_clk_freq = args.sys_clk_freq, revision = args.revision, **parser.soc_argdict ) builder = Builder(soc, **parser.builder_argdict) if args.build: builder.build(**parser.toolchain_argdict) if args.flash: from litex.build.dfu import DFUProg prog_gw = DFUProg(vid="1d50", pid="0x6146", alt=0) prog_sw = DFUProg(vid="1d50", pid="0x6146", alt=1) prog_gw.load_bitstream(builder.get_bitstream_filename(mode="sram", ext=".bin"), reset=False) # FIXME prog_sw.load_bitstream(builder.get_bios_filename()) if __name__ == "__main__": main()