milkymist/m1crg/__init__.py

   1 from fractions import Fraction
   2
   3 from migen.fhdl.structure import *
   4
   5 class M1CRG:
   6         def __init__(self, infreq, outfreq1x):
   7                 self.clkin = Signal()
   8                 self.trigger_reset = Signal()
   9
  10                 self.cd_sys = ClockDomain("sys")
  11
  12                 ratio = Fraction(outfreq1x)/Fraction(infreq)
  13                 in_period = float(Fraction(1000000000)/Fraction(infreq))
  14
  15                 inst_items = [
  16                         Instance.Parameter("in_period", in_period),
  17                         Instance.Parameter("f_mult", ratio.numerator),
  18                         Instance.Parameter("f_div", ratio.denominator),
  19                         Instance.Input("clkin", self.clkin),
  20                         Instance.Input("trigger_reset", self.trigger_reset),
  21
  22                         Instance.Output("sys_clk", self.cd_sys.clk),
  23                         Instance.Output("sys_rst", self.cd_sys.rst)
  24                 ]
  25
  26                 for name in [
  27                         "ac97_rst_n",
  28                         "videoin_rst_n",
  29                         "flash_rst_n",
  30                         "clk2x_270",
  31                         "clk4x_wr",
  32                         "clk4x_wr_strb",
  33                         "clk4x_rd",
  34                         "clk4x_rd_strb",
  35                         "phy_clk",
  36                         "vga_clk",
  37                         "vga_clk_pad"
  38                 ]:
  39                         s = Signal(name=name)
  40                         setattr(self, name, s)
  41                         inst_items.append(Instance.Output(name, s))
  42
  43                 self._inst = Instance("m1crg", *inst_items)
  44
  45
  46         def get_fragment(self):
  47                 return Fragment(instances=[self._inst])