litex/misoc/cores/dvi_sampler/clocking.py

82 lines
3.2 KiB
Python

from migen import *
from migen.genlib.cdc import MultiReg
from misoc.interconnect.csr import *
class Clocking(Module, AutoCSR):
def __init__(self, pads):
self._pll_reset = CSRStorage(reset=1)
self._locked = CSRStatus()
# DRP
self._pll_adr = CSRStorage(5)
self._pll_dat_r = CSRStatus(16)
self._pll_dat_w = CSRStorage(16)
self._pll_read = CSR()
self._pll_write = CSR()
self._pll_drdy = CSRStatus()
self.locked = Signal()
self.serdesstrobe = Signal()
self.clock_domains._cd_pix = ClockDomain()
self.clock_domains._cd_pix2x = ClockDomain()
self.clock_domains._cd_pix10x = ClockDomain(reset_less=True)
###
clk_se = Signal()
self.specials += Instance("IBUFDS", i_I=pads.clk_p, i_IB=pads.clk_n, o_O=clk_se)
clkfbout = Signal()
pll_locked = Signal()
pll_clk0 = Signal()
pll_clk1 = Signal()
pll_clk2 = Signal()
pll_drdy = Signal()
self.sync += If(self._pll_read.re | self._pll_write.re,
self._pll_drdy.status.eq(0)
).Elif(pll_drdy,
self._pll_drdy.status.eq(1)
)
self.specials += Instance("PLL_ADV",
p_CLKFBOUT_MULT=10,
p_CLKOUT0_DIVIDE=1, # pix10x
p_CLKOUT1_DIVIDE=5, # pix2x
p_CLKOUT2_DIVIDE=10, # pix
p_COMPENSATION="INTERNAL",
i_CLKINSEL=1,
i_CLKIN1=clk_se,
o_CLKOUT0=pll_clk0, o_CLKOUT1=pll_clk1, o_CLKOUT2=pll_clk2,
o_CLKFBOUT=clkfbout, i_CLKFBIN=clkfbout,
o_LOCKED=pll_locked, i_RST=self._pll_reset.storage,
i_DADDR=self._pll_adr.storage,
o_DO=self._pll_dat_r.status,
i_DI=self._pll_dat_w.storage,
i_DEN=self._pll_read.re | self._pll_write.re,
i_DWE=self._pll_write.re,
o_DRDY=pll_drdy,
i_DCLK=ClockSignal())
locked_async = Signal()
self.specials += [
Instance("BUFPLL", p_DIVIDE=5,
i_PLLIN=pll_clk0, i_GCLK=ClockSignal("pix2x"), i_LOCKED=pll_locked,
o_IOCLK=self._cd_pix10x.clk, o_LOCK=locked_async, o_SERDESSTROBE=self.serdesstrobe),
Instance("BUFG", i_I=pll_clk1, o_O=self._cd_pix2x.clk),
Instance("BUFG", i_I=pll_clk2, o_O=self._cd_pix.clk),
MultiReg(locked_async, self.locked, "sys")
]
self.comb += self._locked.status.eq(self.locked)
# sychronize pix+pix2x reset
pix_rst_n = 1
for i in range(2):
new_pix_rst_n = Signal()
self.specials += Instance("FDCE", i_D=pix_rst_n, i_CE=1, i_C=ClockSignal("pix"),
i_CLR=~locked_async, o_Q=new_pix_rst_n)
pix_rst_n = new_pix_rst_n
self.comb += self._cd_pix.rst.eq(~pix_rst_n), self._cd_pix2x.rst.eq(~pix_rst_n)