#!/usr/bin/env python3 # # This file is part of LiteX-Boards. # # Copyright (c) 2015 Robert Jordens # Copyright (c) 2015 Sebastien Bourdeauducq # Copyright (c) 2015 Yann Sionneau # Copyright (c) 2016-2017 Tim 'mithro' Ansell # Copyright (c) 2019 Florent Kermarrec # SPDX-License-Identifier: BSD-2-Clause from fractions import Fraction from migen import * from migen.genlib.resetsync import AsyncResetSynchronizer from litex_boards.platforms import pipistrello from litex.soc.integration.soc_core import * from litex.soc.integration.builder import * from litex.soc.cores.led import LedChaser from litedram.modules import MT46H32M16 from litedram.phy import s6ddrphy # CRG ---------------------------------------------------------------------------------------------- class _CRG(Module): def __init__(self, platform, sys_clk_freq): self.rst = Signal() self.clock_domains.cd_sys = ClockDomain() self.clock_domains.cd_sdram_half = ClockDomain() self.clock_domains.cd_sdram_full_wr = ClockDomain() self.clock_domains.cd_sdram_full_rd = ClockDomain() self.reset = Signal() # # # # Input clock ------------------------------------------------------------------------------ clk50_freq = int(50e6) clk50 = platform.request("clk50") clk50b = Signal() self.specials += Instance("BUFIO2", p_DIVIDE=1, p_DIVIDE_BYPASS="TRUE", p_I_INVERT="FALSE", i_I=clk50, o_DIVCLK=clk50b) # PLL -------------------------------------------------------------------------------------- pll_lckd = Signal() pll_fb = Signal() pll_sdram_full = Signal() pll_sdram_half_a = Signal() pll_sdram_half_b = Signal() pll_unused = Signal() pll_sys = Signal() pll_periph = Signal() p = 12 f = Fraction(sys_clk_freq*p, clk50_freq) n, d = f.numerator, f.denominator assert 19e6 <= clk50_freq/d <= 500e6 # pfd assert 400e6 <= clk50_freq*n/d <= 1080e6 # vco self.specials.pll = Instance( "PLL_ADV", name="crg_pll_adv", p_SIM_DEVICE="SPARTAN6", p_BANDWIDTH="OPTIMIZED", p_COMPENSATION="INTERNAL", p_REF_JITTER=.01, i_DADDR=0, i_DCLK=0, i_DEN=0, i_DI=0, i_DWE=0, i_RST=0, i_REL=0, p_DIVCLK_DIVIDE=d, # Input Clocks (50MHz) i_CLKIN1=clk50b, p_CLKIN1_PERIOD=1e9/clk50_freq, i_CLKIN2=0, p_CLKIN2_PERIOD=0., i_CLKINSEL=1, # Feedback i_CLKFBIN=pll_fb, o_CLKFBOUT=pll_fb, o_LOCKED=pll_lckd, p_CLK_FEEDBACK="CLKFBOUT", p_CLKFBOUT_MULT=n, p_CLKFBOUT_PHASE=0., # (333MHz) sdram wr rd o_CLKOUT0=pll_sdram_full, p_CLKOUT0_DUTY_CYCLE=.5, p_CLKOUT0_PHASE=0., p_CLKOUT0_DIVIDE=p//4, # unused? o_CLKOUT1=pll_unused, p_CLKOUT1_DUTY_CYCLE=.5, p_CLKOUT1_PHASE=0., p_CLKOUT1_DIVIDE=15, # (166MHz) sdram_half - sdram dqs adr ctrl o_CLKOUT2=pll_sdram_half_a, p_CLKOUT2_DUTY_CYCLE=.5, p_CLKOUT2_PHASE=270., p_CLKOUT2_DIVIDE=p//2, # (166MHz) off-chip ddr o_CLKOUT3=pll_sdram_half_b, p_CLKOUT3_DUTY_CYCLE=.5, p_CLKOUT3_PHASE=250., p_CLKOUT3_DIVIDE=p//2, # ( 50MHz) periph o_CLKOUT4=pll_periph, p_CLKOUT4_DUTY_CYCLE=.5, p_CLKOUT4_PHASE=0., p_CLKOUT4_DIVIDE=20, # ( 83MHz) sysclk o_CLKOUT5=pll_sys, p_CLKOUT5_DUTY_CYCLE=.5, p_CLKOUT5_PHASE=0., p_CLKOUT5_DIVIDE=p//1, ) # Power on reset reset = platform.request("user_btn") | self.reset | self.rst self.clock_domains.cd_por = ClockDomain() por = Signal(max=1 << 11, reset=(1 << 11) - 1) self.sync.por += If(por != 0, por.eq(por - 1)) self.specials += AsyncResetSynchronizer(self.cd_por, reset) # System clock self.specials += Instance("BUFG", i_I=pll_sys, o_O=self.cd_sys.clk) self.comb += self.cd_por.clk.eq(self.cd_sys.clk) self.specials += AsyncResetSynchronizer(self.cd_sys, ~pll_lckd | (por > 0)) # SDRAM clocks ----------------------------------------------------------------------------- self.clk4x_wr_strb = Signal() self.clk4x_rd_strb = Signal() # SDRAM full clock self.specials += Instance("BUFPLL", name="sdram_full_bufpll", p_DIVIDE = 4, i_PLLIN = pll_sdram_full, i_GCLK=self.cd_sys.clk, i_LOCKED = pll_lckd, o_IOCLK = self.cd_sdram_full_wr.clk, o_SERDESSTROBE = self.clk4x_wr_strb) self.comb += [ self.cd_sdram_full_rd.clk.eq(self.cd_sdram_full_wr.clk), self.clk4x_rd_strb.eq(self.clk4x_wr_strb), ] # SDRAM_half clock self.specials += Instance("BUFG", name="sdram_half_a_bufpll", i_I=pll_sdram_half_a, o_O=self.cd_sdram_half.clk) clk_sdram_half_shifted = Signal() self.specials += Instance("BUFG", name="sdram_half_b_bufpll", i_I=pll_sdram_half_b, o_O=clk_sdram_half_shifted) clk = platform.request("ddram_clock") self.specials += Instance("ODDR2", p_DDR_ALIGNMENT="NONE", p_INIT=0, p_SRTYPE="SYNC", i_D0=1, i_D1=0, i_S=0, i_R=0, i_CE=1, i_C0=clk_sdram_half_shifted, i_C1=~clk_sdram_half_shifted, o_Q=clk.p) self.specials += Instance("ODDR2", p_DDR_ALIGNMENT="NONE", p_INIT=0, p_SRTYPE="SYNC", i_D0=0, i_D1=1, i_S=0, i_R=0, i_CE=1, i_C0=clk_sdram_half_shifted, i_C1=~clk_sdram_half_shifted, o_Q=clk.n) # BaseSoC ------------------------------------------------------------------------------------------ class BaseSoC(SoCCore): def __init__(self, with_led_chaser=True, **kwargs): sys_clk_freq = (83 + Fraction(1, 3))*1000*1000 platform = pipistrello.Platform() # SoCCore ---------------------------------------------------------------------------------- SoCCore.__init__(self, platform, sys_clk_freq, ident = "LiteX SoC on Pipistrello", **kwargs) # CRG -------------------------------------------------------------------------------------- self.submodules.crg = _CRG(platform, sys_clk_freq) self.platform.add_period_constraint(self.crg.cd_sys.clk, 1e9/sys_clk_freq) # LPDDR SDRAM ------------------------------------------------------------------------------ if not self.integrated_main_ram_size: self.submodules.ddrphy = s6ddrphy.S6HalfRateDDRPHY(platform.request("ddram"), memtype = "LPDDR", rd_bitslip = 1, wr_bitslip = 3, dqs_ddr_alignment = "C1") self.comb += [ self.ddrphy.clk4x_wr_strb.eq(self.crg.clk4x_wr_strb), self.ddrphy.clk4x_rd_strb.eq(self.crg.clk4x_rd_strb), ] self.add_sdram("sdram", phy = self.ddrphy, module = MT46H32M16(sys_clk_freq, "1:2"), l2_cache_size = kwargs.get("l2_size", 8192) ) # Leds ------------------------------------------------------------------------------------- if with_led_chaser: self.submodules.leds = LedChaser( pads = platform.request_all("user_led"), sys_clk_freq = sys_clk_freq) # Build -------------------------------------------------------------------------------------------- def main(): from litex.soc.integration.soc import LiteXSoCArgumentParser parser = LiteXSoCArgumentParser(description="LiteX SoC on Pipistrello") target_group = parser.add_argument_group(title="Target options") target_group.add_argument("--build", action="store_true", help="Build bitstream.") target_group.add_argument("--load", action="store_true", help="Load bitstream.") builder_args(parser) soc_core_args(parser) args = parser.parse_args() soc = BaseSoC(**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(builder.get_bitstream_filename(mode="sram")) if __name__ == "__main__": main()