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serwb/scrambler: dynamic enable/disable

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This commit is contained in:
Florent Kermarrec 2018-04-17 19:20:06 +02:00
parent 816a6f2ec7
commit ebfac36223
1 changed files with 62 additions and 60 deletions
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122
artiq/gateware/serwb/scrambler.py
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@ -31,81 +31,83 @@ class _Scrambler(Module):
class Scrambler(Module):
def __init__(self, sync_interval=1024, enable=True):
def __init__(self, sync_interval=1024):
self.enable = Signal()
self.sink = sink = stream.Endpoint([("data", 32)])
self.source = source = stream.Endpoint([("d", 32), ("k", 4)])
# # #
if enable:
# scrambler
self.submodules.scrambler = scrambler = _Scrambler(32)
# scrambler
self.submodules.scrambler = scrambler = _Scrambler(32)
# insert K.29.7 as sync character
# every sync_interval cycles
count = Signal(max=sync_interval)
self.submodules.fsm = fsm = FSM(reset_state="SYNC")
fsm.act("SYNC",
scrambler.reset.eq(1),
source.stb.eq(1),
source.k[0].eq(1),
source.d[:8].eq(K(29, 7)),
NextValue(count, 0),
If(source.ack,
NextState("DATA")
# insert K.29.7 as sync character
# every sync_interval cycles
count = Signal(max=sync_interval)
self.submodules.fsm = fsm = ResetInserter()(FSM(reset_state="DISABLE"))
self.comb += fsm.reset.eq(~self.enable)
fsm.act("DISABLE",
sink.connect(source, omit={"data"}),
source.k.eq(0b0000),
source.d.eq(sink.data),
NextState("SYNC")
)
fsm.act("SYNC",
scrambler.reset.eq(1),
source.stb.eq(1),
source.k[0].eq(1),
source.d[:8].eq(K(29, 7)),
NextValue(count, 0),
If(source.ack,
NextState("DATA")
)
)
fsm.act("DATA",
scrambler.i.eq(sink.data),
sink.ack.eq(source.ack),
source.stb.eq(1),
source.d.eq(scrambler.o),
If(source.stb & source.ack,
scrambler.ce.eq(1),
NextValue(count, count + 1),
If(count == (sync_interval - 1),
NextState("SYNC")
)
)
fsm.act("DATA",
scrambler.i.eq(sink.data),
sink.ack.eq(source.ack),
source.stb.eq(1),
source.d.eq(scrambler.o),
If(source.stb & source.ack,
scrambler.ce.eq(1),
NextValue(count, count + 1),
If(count == (sync_interval - 1),
NextState("SYNC")
)
)
)
else:
self.comb += [
sink.connect(source, omit={"data"}),
source.k.eq(0b0000),
source.d.eq(sink.data)
]
)
class Descrambler(Module):
def __init__(self, enable=True):
def __init__(self):
self.enable = Signal()
self.sink = sink = stream.Endpoint([("d", 32), ("k", 4)])
self.source = source = stream.Endpoint([("data", 32)])
# # #
if enable:
# descrambler
self.submodules.descrambler = descrambler = _Scrambler(32)
self.comb += descrambler.i.eq(sink.d)
# descrambler
self.submodules.descrambler = descrambler = _Scrambler(32)
self.comb += descrambler.i.eq(sink.d)
# detect K29.7 and synchronize descrambler
self.comb += [
descrambler.reset.eq(0),
If((sink.k[0] == 1) &
(sink.d[:8] == K(29,7)),
sink.ack.eq(1),
descrambler.reset.eq(1)
).Else(
sink.ack.eq(source.ack),
source.stb.eq(sink.stb),
source.data.eq(descrambler.o),
If(source.stb & source.ack,
descrambler.ce.eq(1)
)
# detect K29.7 and synchronize descrambler
self.submodules.fsm = fsm = ResetInserter()(FSM(reset_state="DISABLE"))
self.comb += fsm.reset.eq(~self.enable)
fsm.act("DISABLE",
sink.connect(source, omit={"d", "k"}),
source.data.eq(sink.d),
NextState("SYNC_DATA")
)
fsm.act("SYNC_DATA",
If((sink.k[0] == 1) &
(sink.d[:8] == K(29,7)),
sink.ack.eq(1),
descrambler.reset.eq(1)
).Else(
sink.ack.eq(source.ack),
source.stb.eq(sink.stb),
source.data.eq(descrambler.o),
If(source.stb & source.ack,
descrambler.ce.eq(1)
)
]
else:
self.comb += [
sink.connect(source, omit={"d", "k"}),
source.data.eq(sink.d)
]
)
)