import argparse
from migen import *
+from migen.genlib.resetsync import AsyncResetSynchronizer
-from litex.boards.platforms import de0nano
+from litex_boards.platforms import de0nano
from litex.soc.integration.soc_sdram import *
from litex.soc.integration.builder import *
def __init__(self, platform):
self.clock_domains.cd_sys = ClockDomain()
self.clock_domains.cd_sys_ps = ClockDomain()
- self.clock_domains.cd_por = ClockDomain(reset_less=True)
# # #
- # Power on reset
- rst_n = Signal()
- self.sync.por += rst_n.eq(1)
- self.comb += [
- self.cd_por.clk.eq(self.cd_sys.clk),
- self.cd_sys.rst.eq(~rst_n),
- self.cd_sys_ps.rst.eq(~rst_n)
- ]
-
- # Sys Clk / SDRAM Clk
+ # Clk / Rst
clk50 = platform.request("clk50")
- self.comb += self.cd_sys.clk.eq(clk50)
+ platform.add_period_constraint(clk50, 1e9/50e6)
+
+ # PLL
+ pll_locked = Signal()
+ pll_clk_out = Signal(6)
self.specials += \
Instance("ALTPLL",
p_BANDWIDTH_TYPE = "AUTO",
p_CLK0_DIVIDE_BY = 1,
p_CLK0_DUTY_CYCLE = 50,
p_CLK0_MULTIPLY_BY = 1,
- p_CLK0_PHASE_SHIFT = "-3000",
+ p_CLK0_PHASE_SHIFT = "0",
+ p_CLK1_DIVIDE_BY = 1,
+ p_CLK1_DUTY_CYCLE = 50,
+ p_CLK1_MULTIPLY_BY = 1,
+ p_CLK1_PHASE_SHIFT = "-10000",
p_COMPENSATE_CLOCK = "CLK0",
p_INCLK0_INPUT_FREQUENCY = 20000,
- p_OPERATION_MODE = "ZERO_DELAY_BUFFER",
+ p_OPERATION_MODE = "NORMAL",
i_INCLK = clk50,
- o_CLK = self.cd_sys_ps.clk,
- i_ARESET = ~rst_n,
+ o_CLK = pll_clk_out,
+ i_ARESET = 0,
i_CLKENA = 0x3f,
i_EXTCLKENA = 0xf,
i_FBIN = 1,
i_PFDENA = 1,
i_PLLENA = 1,
+ o_LOCKED = pll_locked,
)
+ self.comb += [
+ self.cd_sys.clk.eq(pll_clk_out[0]),
+ self.cd_sys_ps.clk.eq(pll_clk_out[1]),
+ ]
+ self.specials += [
+ AsyncResetSynchronizer(self.cd_sys, ~pll_locked),
+ AsyncResetSynchronizer(self.cd_sys_ps, ~pll_locked)
+ ]
+
+ # SDRAM clock
self.comb += platform.request("sdram_clock").eq(self.cd_sys_ps.clk)
# BaseSoC ------------------------------------------------------------------------------------------
self.stop = Signal()
- # clk / rst
+ # Clk / Rst
clk100 = platform.request("clk100")
rst_n = platform.request("rst_n")
platform.add_period_constraint(clk100, 1e9/100e6)
- # power on reset
+ # 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
+ # PLL
self.submodules.pll = pll = ECP5PLL()
pll.register_clkin(clk100, 100e6)
pll.create_clkout(self.cd_sys2x_i, 2*sys_clk_freq)