nmigen_boards/_blinky.py

   1 import itertools
   2
   3 from nmigen import *
   4 from nmigen.build import ResourceError
   5
   6
   7 class Blinky(Elaboratable):
   8     def elaborate(self, platform):
   9         m = Module()
  10
  11         leds = []
  12         for n in itertools.count():
  13             try:
  14                 leds.append(platform.request("user_led", n))
  15             except ResourceError:
  16                 break
  17         leds = Cat(led.o for led in leds)
  18
  19         clk_freq = platform.default_clk_frequency
  20         ctr = Signal(max=int(clk_freq//2), reset=int(clk_freq//2) - 1)
  21         with m.If(ctr == 0):
  22             m.d.sync += ctr.eq(ctr.reset)
  23             m.d.sync += leds.eq(~leds)
  24         with m.Else():
  25             m.d.sync += ctr.eq(ctr - 1)
  26
  27         return m