nmigen_boards/dev/sd.py

   1 from nmigen.build import *
   2
   3
   4 __all__ = ["SDCardResources"]
   5
   6
   7 def SDCardResources(*args, clk, cmd, dat0, dat1=None, dat2=None, dat3=None,
   8                     cd=None, wp=None, attrs=None):
   9     resources = []
  10
  11     io_common = []
  12     if attrs is not None:
  13         io_common.append(attrs)
  14     if cd is not None:
  15         io_common.append(Subsignal("cd", Pins(cd, dir="i", assert_width=1)))
  16     if wp is not None:
  17         io_common.append(Subsignal("wp", PinsN(wp, dir="i", assert_width=1)))
  18
  19     io_native = list(io_common)
  20     io_native.append(Subsignal("clk", Pins(clk, dir="o", assert_width=1)))
  21     io_native.append(Subsignal("cmd", Pins(cmd, dir="o", assert_width=1)))
  22
  23     io_1bit = list(io_native)
  24     io_1bit.append(Subsignal("dat", Pins(dat0, dir="io", assert_width=1)))
  25     if dat3 is not None: # works as electronic card detect
  26         io_1bit.append(Subsignal("ecd", Pins(dat3, dir="i", assert_width=1)))
  27     resources.append(Resource.family(*args, default_name="sd_card", ios=io_1bit,
  28                                      name_suffix="1bit"))
  29
  30     if dat1 is not None and dat2 is not None and dat3 is not None:
  31         io_4bit = list(io_native)
  32         io_4bit.append(Subsignal("dat", Pins(" ".join((dat0, dat1, dat2, dat3)), dir="io",
  33                                              assert_width=4)))
  34         resources.append(Resource.family(*args, default_name="sd_card", ios=io_4bit,
  35                                          name_suffix="4bit"))
  36
  37     if dat3 is not None:
  38         io_spi = list(io_common)
  39         io_spi.append(Subsignal("cs", PinsN(dat3, dir="io"))) # doubles as electronic card detect
  40         io_spi.append(Subsignal("clk", Pins(clk, dir="o", assert_width=1)))
  41         io_spi.append(Subsignal("mosi", Pins(cmd, dir="o", assert_width=1)))
  42         io_spi.append(Subsignal("miso", Pins(dat0, dir="i", assert_width=1)))
  43         resources.append(Resource.family(*args, default_name="sd_card", ios=io_spi,
  44                                          name_suffix="spi"))
  45
  46     return resources