litex/liteeth/core/etherbone/wishbone.py

from liteeth.common import *
from migen.bus import wishbone

class LiteEthEtherboneWishboneMaster(Module):
	def __init__(self):
		self.sink = sink = Sink(eth_etherbone_mmap_description(32))
		self.source = source = Source(eth_etherbone_mmap_description(32))
		self.bus = bus = wishbone.Interface()
		###s

		self.submodules.data = data = FlipFlop(32)
		self.comb += data.d.eq(bus.dat_r)

		self.submodules.fsm = fsm = FSM(reset_state="IDLE")
		fsm.act("IDLE",
			sink.ack.eq(1),
			If(sink.stb & sink.sop,
				sink.ack.eq(0),
				If(sink.we,
					NextState("WRITE_DATA")
				).Else(
					NextState("READ_DATA")
				)
			)
		)
		fsm.act("WRITE_DATA",
			bus.adr.eq(sink.addr),
			bus.dat_w.eq(sink.data),
			bus.sel.eq(sink.be),
			bus.stb.eq(sink.stb),
			bus.we.eq(1),
			bus.cyc.eq(1),
			If(bus.stb & bus.ack,
				sink.ack.eq(1),
				If(sink.eop,
					NextState("IDLE")
				)
			)
		)
		fsm.act("READ_DATA",
			bus.adr.eq(sink.addr),
			bus.sel.eq(sink.be),
			bus.stb.eq(sink.stb),
			bus.cyc.eq(1),
			If(bus.stb & bus.ack,
				data.ce.eq(1),
				NextState("SEND_DATA")
			)
		)
		fsm.act("SEND_DATA",
			source.stb.eq(sink.stb),
			source.sop.eq(sink.sop),
			source.eop.eq(sink.eop),
			source.base_addr.eq(sink.base_addr),
			source.addr.eq(sink.addr),
			source.count.eq(sink.count),
			source.be.eq(sink.be),
			source.we.eq(1),
			source.data.eq(data.q),
			If(source.stb & source.ack,
				sink.ack.eq(1),
				If(source.eop,
					NextState("IDLE")
				).Else(
					NextState("READ_DATA")
				)
			)
		)