litex-boards/litex_boards/community/targets/pipistrello.py

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#!/usr/bin/env python3
2019-12-31 11:44:24 -05:00
# This file is Copyright (c) 2015 Robert Jordens <jordens@gmail.com>
# This file is Copyright (c) 2015 Sebastien Bourdeauducq <sb@m-labs.hk>
# This file is Copyright (c) 2015 Yann Sionneau <yann.sionneau@gmail.com>
# This file is Copyright (c) 2016-2017 Tim 'mithro' Ansell <mithro@mithis.com>
# This file is Copyright (c) 2019 Florent Kermarrec <florent@enjoy-digital.fr>
2019-12-31 11:44:24 -05:00
# License: BSD
import argparse
from fractions import Fraction
from migen import *
from migen.genlib.resetsync import AsyncResetSynchronizer
from litex_boards.platforms import pipistrello
from litex.soc.integration.soc_sdram import *
from litex.soc.integration.builder import *
from litedram.modules import MT46H32M16
from litedram.phy import s6ddrphy
# CRG ----------------------------------------------------------------------------------------------
class _CRG(Module):
def __init__(self, platform, sys_clk_freq):
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.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(SoCSDRAM):
def __init__(self, **kwargs):
sys_clk_freq = (83 + Fraction(1, 3))*1000*1000
platform = pipistrello.Platform()
# SoCSDRAM ---------------------------------------------------------------------------------
SoCSDRAM.__init__(self, platform, clk_freq=sys_clk_freq, **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 ------------------------------------------------------------------------------
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_csr("ddrphy")
sdram_module = MT46H32M16(sys_clk_freq, "1:2")
self.register_sdram(self.ddrphy,
geom_settings = sdram_module.geom_settings,
timing_settings = sdram_module.timing_settings)
# Build --------------------------------------------------------------------------------------------
def main():
parser = argparse.ArgumentParser(description="LiteX SoC on Pipistrello")
builder_args(parser)
soc_sdram_args(parser)
args = parser.parse_args()
soc = BaseSoC(**soc_sdram_argdict(args))
builder = Builder(soc, **builder_argdict(args))
builder.build()
if __name__ == "__main__":
main()