litex/misoclib/tools/litescope/bridge/wishbone.py

147 lines
4.5 KiB
Python

from misoclib.tools.litescope.common import *
from migen.bus import wishbone
from migen.genlib.misc import chooser
from migen.genlib.record import Record
from migen.flow.actor import Sink, Source
from misoclib.com.uart.phy.serial import UARTPHYSerial
class LiteScopeWishboneBridge(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"))
timeout = Timeout(clk_freq//10)
self.submodules += fsm, timeout
self.comb += [
timeout.ce.eq(1),
fsm.reset.eq(timeout.reached),
phy.source.ack.eq(1)
]
fsm.act("IDLE",
timeout.reset.eq(1),
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)
)
)
)
)
class LiteScopeUART2Wishbone(LiteScopeWishboneBridge):
def __init__(self, pads, clk_freq, baudrate=115200):
self.submodules.phy = UARTPHYSerial(pads, clk_freq, baudrate)
LiteScopeWishboneBridge.__init__(self, self.phy, clk_freq)