litex/liteeth/core/etherbone/master.py

92 lines
2.1 KiB
Python

from liteeth.common import *
from liteeth.core.etherbone import common
class LiteEthEtherboneWishboneMaster(Module):
def __init__(self):
self.sink = sink = Sink(eth_etherbone_user_description(32))
self.source = source = Source(eth_etherbone_description(32))
self.bus = bus = wishbone.Interface()
###
self.submodules.base_addr = base_addr = FlipFlop(32)
self.comb += self.base_addr.d.eq(self.sink.data)
self.submodules.counter = counter = Counter(32)
self.submodules.fifo = fifo = SyncFIFO([("data", 32)], 256)
self.submodules.fsm = fsm = FSM(reset_state="IDLE")
fsm.act("IDLE",
sink.ack.eq(1),
counter.reset.eq(1),
If(sink.stb & sink.sop,
If(sink.wcount > 0,
self.base_addr.ce.eq(1),
NextState("WRITE_DATA")
).Elif(sink.rcount > 0,
self.base_addr.ce.eq(1),
NextState("READ_DATA")
)
)
)
fsm.act("WRITE_DATA",
bus.adr.eq(base_addr + self.counter.value),
bus.dat_w.eq(sink.data),
bus.sel.eq(0xf), # XXX?
bus.stb.eq(sink.stb),
bus.we.eq(1),
bus.cyc.eq(1),
If(bus.stb & bus.ack,
sink.ack.eq(1),
counter.ce.eq(1),
If(counter.value == sink.wcount-1,
If(sink.rcount > 0,
counter.reset.eq(1)
NextState("READ_DATA")
).Else(
NextState("TERMINATE")
)
)
)
)
fsm.act("CHECK_READ",
If(sink.rcount > 0,
If(sink.stb,
sink.ack.eq(1),
base_addr.ce.eq(1),
NextState("READ_DATA")
)
).Else(
NextState("IDLE")
)
)
fsm.act("READ_DATA",
bus.adr.eq(self.sink.data),
bus.sel.eq(0xf),
bus.stb.eq(1),
bus.we.eq(0),
bus.cyc.eq(1),
If(bus.stb & bus.ack,
sink.ack.eq(1),
counter.ce.eq(1),
fifo.sink.stb.eq(1),
fifo.sink.sop.eq(counter == 0),
fifo.sink.data.eq(bus.dat_r),
If(counter.value == sink.rcount-1,
fifo.sink.eop.eq(1),
NextState("PRESENT_DATA")
)
)
)
fsm.act("PRESENT_DATA",
source.stb.eq(fifo.stb),
source.sop.eq(fifo.sop),
source.eop.eq(fifo.eop),
fifo.ack.eq(source.ack),
source.length.eq(sink.rcount+1),
source.wcount.eq(sink.rcount),
source.rcount.eq(0),
If(source.stb & source.eop & source.ack,
NextState("IDLE")
)
)