soc/interconnect: add wishbonebridge and uart bridge

This commit is contained in:
Florent Kermarrec 2015-11-12 00:52:36 +01:00
parent 89b189ce4a
commit 525da89c7d
2 changed files with 170 additions and 0 deletions

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from migen import *
from litex.soc.interconnect.wishbonebridge import WishboneStreamingBridge
from litex.soc.cores.uart.core import RS232PHY
class UARTWishboneBridge(WishboneStreamingBridge):
def __init__(self, pads, clk_freq, baudrate=115200):
self.submodules.phy = RS232PHY(pads, clk_freq, baudrate)
WishboneStreamingBridge.__init__(self, self.phy, clk_freq)

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from migen import *
from migen.genlib.misc import chooser, WaitTimer
from migen.genlib.record import Record
from migen.genlib.fsm import FSM, NextState
from litex.soc.interconnect import wishbone
from litex.soc.interconnect.stream import Sink, Source
@ResetInserter()
@CEInserter()
class Counter(Module):
def __init__(self, *args, increment=1, **kwargs):
self.value = Signal(*args, **kwargs)
self.width = flen(self.value)
self.sync += self.value.eq(self.value+increment)
class WishboneStreamingBridge(Module):
cmds = {
"write": 0x01,
"read": 0x02
}
def __init__(self, phy, clk_freq):
self.wishbone = wishbone.Interface()
# # #
byte_counter = Counter(3)
word_counter = Counter(8)
self.submodules += byte_counter, word_counter
cmd = Signal(8)
cmd_ce = Signal()
length = Signal(8)
length_ce = Signal()
address = Signal(32)
address_ce = Signal()
data = Signal(32)
rx_data_ce = Signal()
tx_data_ce = Signal()
self.sync += [
If(cmd_ce, cmd.eq(phy.source.data)),
If(length_ce, length.eq(phy.source.data)),
If(address_ce, address.eq(Cat(phy.source.data, address[0:24]))),
If(rx_data_ce,
data.eq(Cat(phy.source.data, data[0:24]))
).Elif(tx_data_ce,
data.eq(self.wishbone.dat_r)
)
]
fsm = InsertReset(FSM(reset_state="IDLE"))
timer = WaitTimer(clk_freq//10)
self.submodules += fsm, timer
self.comb += [
fsm.reset.eq(timer.done),
phy.source.ack.eq(1)
]
fsm.act("IDLE",
If(phy.source.stb,
cmd_ce.eq(1),
If((phy.source.data == self.cmds["write"]) |
(phy.source.data == self.cmds["read"]),
NextState("RECEIVE_LENGTH")
),
byte_counter.reset.eq(1),
word_counter.reset.eq(1)
)
)
fsm.act("RECEIVE_LENGTH",
If(phy.source.stb,
length_ce.eq(1),
NextState("RECEIVE_ADDRESS")
)
)
fsm.act("RECEIVE_ADDRESS",
If(phy.source.stb,
address_ce.eq(1),
byte_counter.ce.eq(1),
If(byte_counter.value == 3,
If(cmd == self.cmds["write"],
NextState("RECEIVE_DATA")
).Elif(cmd == self.cmds["read"],
NextState("READ_DATA")
),
byte_counter.reset.eq(1),
)
)
)
fsm.act("RECEIVE_DATA",
If(phy.source.stb,
rx_data_ce.eq(1),
byte_counter.ce.eq(1),
If(byte_counter.value == 3,
NextState("WRITE_DATA"),
byte_counter.reset.eq(1)
)
)
)
self.comb += [
self.wishbone.adr.eq(address + word_counter.value),
self.wishbone.dat_w.eq(data),
self.wishbone.sel.eq(2**flen(self.wishbone.sel)-1)
]
fsm.act("WRITE_DATA",
self.wishbone.stb.eq(1),
self.wishbone.we.eq(1),
self.wishbone.cyc.eq(1),
If(self.wishbone.ack,
word_counter.ce.eq(1),
If(word_counter.value == (length-1),
NextState("IDLE")
).Else(
NextState("RECEIVE_DATA")
)
)
)
fsm.act("READ_DATA",
self.wishbone.stb.eq(1),
self.wishbone.we.eq(0),
self.wishbone.cyc.eq(1),
If(self.wishbone.ack,
tx_data_ce.eq(1),
NextState("SEND_DATA")
)
)
self.comb += \
chooser(data, byte_counter.value, phy.sink.data, n=4, reverse=True)
fsm.act("SEND_DATA",
phy.sink.stb.eq(1),
If(phy.sink.ack,
byte_counter.ce.eq(1),
If(byte_counter.value == 3,
word_counter.ce.eq(1),
If(word_counter.value == (length-1),
NextState("IDLE")
).Else(
NextState("READ_DATA"),
byte_counter.reset.eq(1)
)
)
)
)
self.comb += timer.wait.eq(~fsm.ongoing("IDLE"))
if phy.sink.description.packetized:
self.comb += [
phy.sink.sop.eq((byte_counter.value == 0) & (word_counter.value == 0)),
phy.sink.eop.eq((byte_counter.value == 3) & (word_counter.value == (length-1)))
]
if hasattr(phy.sink, "length"):
self.comb += phy.sink.length.eq(4*length)