litex/liteeth/mac/frontend/wishbone.py

40 lines
1.4 KiB
Python

from liteeth.common import *
from liteeth.mac.common import *
from liteeth.mac.frontend import sram
from migen.bus import wishbone
from migen.fhdl.simplify import FullMemoryWE
class LiteEthMACWishboneInterface(Module, AutoCSR):
def __init__(self, dw, nrxslots=2, ntxslots=2):
self.sink = Sink(eth_mac_description(dw))
self.source = Source(eth_mac_description(dw))
self.bus = wishbone.Interface()
###
# storage in SRAM
sram_depth = buffer_depth//(dw//8)
self.submodules.sram = sram.LiteEthMACSRAM(dw, sram_depth, nrxslots, ntxslots)
self.comb += [
Record.connect(self.sink, self.sram.sink),
Record.connect(self.sram.source, self.source)
]
# Wishbone interface
wb_rx_sram_ifs = [wishbone.SRAM(self.sram.writer.mems[n], read_only=True)
for n in range(nrxslots)]
# TODO: FullMemoryWE should move to Mibuild
wb_tx_sram_ifs = [FullMemoryWE(wishbone.SRAM(self.sram.reader.mems[n], read_only=False))
for n in range(ntxslots)]
wb_sram_ifs = wb_rx_sram_ifs + wb_tx_sram_ifs
wb_slaves = []
decoderoffset = log2_int(sram_depth)
decoderbits = log2_int(len(wb_sram_ifs))
for n, wb_sram_if in enumerate(wb_sram_ifs):
def slave_filter(a, v=n):
return a[decoderoffset:decoderoffset+decoderbits] == v
wb_slaves.append((slave_filter, wb_sram_if.bus))
self.submodules += wb_sram_if
wb_con = wishbone.Decoder(self.bus, wb_slaves, register=True)
self.submodules += wb_con