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kc705: generate sys_clk from the same clock source used for clocking the transceiver (to avoid backpressure issues with daisho core)

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This commit is contained in:
Florent Kermarrec 2019-12-03 19:26:36 +01:00
parent f2e20c64ab
commit 27e6f389c8
1 changed files with 19 additions and 5 deletions
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24
kc705.py
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@ -53,14 +53,14 @@ _usb3_io = [
# CRG ----------------------------------------------------------------------------------------------
class _CRG(Module):
def __init__(self, platform, sys_clk_freq):
def __init__(self, platform, refclk62p5, sys_clk_freq):
self.clock_domains.cd_sys = ClockDomain()
self.clock_domains.cd_usb3_oob = ClockDomain()
# # #
self.submodules.pll = pll = S7PLL(speedgrade=-2)
pll.register_clkin(platform.request("clk156"), 156.5e6)
pll.register_clkin(refclk62p5, 62.5e6)
pll.create_clkout(self.cd_sys, sys_clk_freq)
pll.create_clkout(self.cd_usb3_oob, sys_clk_freq/8)
@ -69,11 +69,25 @@ class _CRG(Module):
class USB3SoC(SoCMini):
def __init__(self, platform, connector="pcie", with_etherbone=True, with_analyzer=True):
sys_clk_freq = int(156.5e6)
sys_clk_freq = int(125e6)
SoCMini.__init__(self, platform, sys_clk_freq, ident="USB3SoC", ident_version=True)
# 125MHz RefClk ----------------------------------------------------------------------------
sgmii_clk = platform.request("sgmii_clock")
refclk125 = Signal()
refclk62p5 = Signal()
self.specials += [
Instance("IBUFDS_GTE2",
i_CEB = 0,
i_I = sgmii_clk.p,
i_IB = sgmii_clk.n,
o_O = refclk125,
o_ODIV2 = refclk62p5,
)
]
# CRG --------------------------------------------------------------------------------------
self.submodules.crg = _CRG(platform, sys_clk_freq)
self.submodules.crg = _CRG(platform, refclk62p5, sys_clk_freq)
# Ethernet <--> Wishbone -------------------------------------------------------------------
if with_etherbone:
@ -109,7 +123,7 @@ class USB3SoC(SoCMini):
usb3_serdes = K7USB3SerDes(platform,
sys_clk = self.crg.cd_sys.clk,
sys_clk_freq = sys_clk_freq,
refclk_pads = platform.request("sgmii_clock"),
refclk_pads = refclk125,
refclk_freq = 125e6,
tx_pads = platform.request(connector + "_tx"),
rx_pads = platform.request(connector + "_rx"))