litex/liteeth/mac/frontend/wishbone.py

from liteeth.common import *
from liteeth.mac.common import *
from liteeth.mac.frontend import sram

class LiteEthMACWishboneInterface(Module, AutoCSR):
	def __init__(self, dw, nrxslots=2, ntxslots=2):
		self.sink = Sink(mac_description(dw))
		self.source = Source(max_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