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                 generated = []
  11                 for name in [
  12                         "sys_clk",
  13                         "sys_rst",
  14                         "ac97_rst_n",
  15                         "videoin_rst_n",
  16                         "flash_rst_n",
  17                         "clk2x_90",
  18                         "clk4x_wr",
  19                         "clk4x_wr_strb",
  20                         "clk4x_rd",
  21                         "clk4x_rd_strb"
  22                 ]:
  23                         s = Signal(name=name)
  24                         setattr(self, name, s)
  25                         generated.append((name, s))
  26
  27                 ratio = Fraction(outfreq1x)/Fraction(infreq)
  28                 in_period = float(Fraction(1000000000)/Fraction(infreq))
  29
  30                 self._inst = Instance("m1crg",
  31                         generated,
  32                         [
  33                                 ("clkin", self.clkin),
  34                                 ("trigger_reset", self.trigger_reset)
  35                         ],
  36                         parameters=[
  37                                 ("in_period", in_period),
  38                                 ("f_mult", ratio.numerator),
  39                                 ("f_div", ratio.denominator)
  40                         ]
  41                 )
  42
  43         def get_fragment(self):
  44                 return Fragment(instances=[self._inst],
  45                         pads={self.clkin, self.ac97_rst_n, self.videoin_rst_n, self.flash_rst_n})