liteeth/common.py

   1 from collections import OrderedDict
   2
   3 from migen.fhdl.std import *
   4 from migen.fhdl.std import *
   5 from migen.flow.actor import Sink, Source
   6 from migen.bank.description import *
   7 from migen.genlib.resetsync import AsyncResetSynchronizer
   8 from migen.flow.actor import EndpointDescription
   9
  10 eth_mtu = 1532
  11 eth_preamble = 0xD555555555555555
  12 buffer_depth = 2**log2_int(eth_mtu, need_pow2=False)
  13
  14 def eth_description(dw):
  15         layout = [
  16                 ("d", dw),
  17                 ("last_be", dw//8),
  18                 ("error", dw//8)
  19         ]
  20         return EndpointDescription(layout, packetized=True)