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gateware/serwb: cleanup packet

This commit is contained in:
Florent Kermarrec 2018-01-03 17:30:12 +01:00
parent 08dada9e16
commit 7f4756a869
1 changed files with 39 additions and 38 deletions
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77
artiq/gateware/serwb/packet.py
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@ -89,34 +89,31 @@ class Packetizer(Module):
# - length : 4 bytes
# - payload
fsm = FSM(reset_state="IDLE")
fsm = FSM(reset_state="PREAMBLE")
self.submodules += fsm
fsm.act("IDLE",
fsm.act("PREAMBLE",
If(sink.stb,
NextState("INSERT_PREAMBLE")
source.stb.eq(1),
source.data.eq(0x5aa55aa5),
If(source.ack,
NextState("LENGTH")
)
)
)
fsm.act("INSERT_PREAMBLE",
source.stb.eq(1),
source.data.eq(0x5aa55aa5),
If(source.ack,
NextState("INSERT_LENGTH")
)
)
fsm.act("INSERT_LENGTH",
fsm.act("LENGTH",
source.stb.eq(1),
source.data.eq(sink.length),
If(source.ack,
NextState("COPY")
NextState("DATA")
)
)
fsm.act("COPY",
fsm.act("DATA",
source.stb.eq(sink.stb),
source.data.eq(sink.data),
sink.ack.eq(source.ack),
If(source.ack & sink.eop,
NextState("IDLE")
NextState("PREAMBLE")
)
)
@ -128,45 +125,49 @@ class Depacketizer(Module):
# # #
count = Signal(len(source.length))
length = Signal(len(source.length))
# Packet description
# - preamble : 4 bytes
# - length : 4 bytes
# - payload
fsm = FSM(reset_state="IDLE")
fsm = FSM(reset_state="PREAMBLE")
self.submodules += fsm
self.submodules.timer = WaitTimer(clk_freq*timeout)
self.comb += self.timer.wait.eq(~fsm.ongoing("IDLE"))
timer = WaitTimer(clk_freq*timeout)
self.submodules += timer
fsm.act("IDLE",
fsm.act("PREAMBLE",
sink.ack.eq(1),
If(sink.stb & (sink.data == 0x5aa55aa5),
NextState("RECEIVE_LENGTH")
If(sink.stb &
(sink.data == 0x5aa55aa5),
NextState("LENGTH")
)
)
fsm.act("RECEIVE_LENGTH",
fsm.act("LENGTH",
sink.ack.eq(1),
If(sink.stb,
NextValue(source.length, sink.data),
NextState("COPY")
)
NextValue(count, 0),
NextValue(length, sink.data),
NextState("DATA")
),
timer.wait.eq(1)
)
eop = Signal()
cnt = Signal(32)
fsm.act("COPY",
fsm.act("DATA",
source.stb.eq(sink.stb),
source.eop.eq(eop),
source.eop.eq(count == (length[2:] - 1)),
source.length.eq(length),
source.data.eq(sink.data),
sink.ack.eq(source.ack),
If((source.stb & source.ack & eop) | self.timer.done,
NextState("IDLE")
)
)
self.sync += \
If(fsm.ongoing("IDLE"),
cnt.eq(0)
If(timer.done,
NextState("PREAMBLE")
).Elif(source.stb & source.ack,
cnt.eq(cnt + 1)
)
self.comb += eop.eq(cnt == source.length[2:] - 1)
NextValue(count, count + 1),
If(source.eop,
NextState("PREAMBLE")
)
),
timer.wait.eq(1)
)