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drtio: add buffer space support to rt_packet_repeater

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This commit is contained in:
Sebastien Bourdeauducq 2018-09-02 14:38:37 +08:00
parent 88b7529d09
commit 6768dbab6c
4 changed files with 118 additions and 4 deletions
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4
artiq/gateware/drtio/rt_packet_master.py
View File

@ -15,7 +15,7 @@ class RTPacketMaster(Module):
# standard request interface
#
# notwrite=1 address=0 buffer space request
# notwrite=1 address=0 buffer space request <destination>
# notwrite=1 address=1 read request <channel, timestamp>
#
# optimized for write throughput
@ -252,7 +252,7 @@ class RTPacketMaster(Module):
)
)
tx_fsm.act("BUFFER_SPACE",
tx_dp.send("buffer_space_request"),
tx_dp.send("buffer_space_request", destination=sr_channel),
If(tx_dp.packet_last,
sr_buf_re.eq(1),
NextState("IDLE")

80
artiq/gateware/drtio/rt_packet_repeater.py
View File

@ -1,14 +1,25 @@
from migen import *
from migen.genlib.fsm import *
from migen.genlib.misc import WaitTimer
from artiq.gateware.rtio import cri
from artiq.gateware.drtio.cdc import CrossDomainNotification
from artiq.gateware.drtio.rt_serializer import *
class RTPacketRepeater(Module):
def __init__(self, link_layer):
# CRI target interface in rtio domain
self.cri = cri.Interface()
# in rtio_rx domain
self.err_unknown_packet_type = Signal()
self.err_packet_truncated = Signal()
# in rtio domain
self.buffer_space_timeout = Signal()
# RX/TX datapath
assert len(link_layer.tx_rt_data) == len(link_layer.rx_rt_data)
assert len(link_layer.tx_rt_data) % 8 == 0
@ -61,12 +72,30 @@ class RTPacketRepeater(Module):
extra_data_counter.eq(1)
)
# Buffer space
buffer_space_destination = Signal(8)
self.sync.rtio += If(self.cri.cmd == cri.commands["get_buffer_space"],
buffer_space_destination.eq(self.cri.chan_sel[16:]))
rx_buffer_space_not = Signal()
rx_buffer_space = Signal(16)
buffer_space_not = Signal()
buffer_space_not_ack = Signal()
self.submodules += CrossDomainNotification("rtio_rx", "rtio",
rx_buffer_space_not, rx_buffer_space,
buffer_space_not, buffer_space_not_ack,
self.cri.o_buffer_space)
timeout_counter = WaitTimer(8191)
self.submodules += timeout_counter
# TX FSM
tx_fsm = ClockDomainsRenamer("rtio")(FSM(reset_state="IDLE"))
self.submodules += tx_fsm
tx_fsm.act("IDLE",
If(self.cri.cmd == cri.commands["write"], NextState("WRITE"))
If(self.cri.cmd == cri.commands["write"], NextState("WRITE")),
If(self.cri.cmd == cri.commands["get_buffer_space"], NextState("BUFFER_SPACE"))
)
tx_fsm.act("WRITE",
tx_dp.send("write",
@ -90,3 +119,52 @@ class RTPacketRepeater(Module):
NextState("IDLE")
)
)
tx_fsm.act("BUFFER_SPACE",
tx_dp.send("buffer_space_request", destination=buffer_space_destination),
If(tx_dp.packet_last,
buffer_space_not_ack.eq(1),
NextState("WAIT_BUFFER_SPACE")
)
)
tx_fsm.act("WAIT_BUFFER_SPACE",
timeout_counter.wait.eq(1),
If(timeout_counter.done,
self.buffer_space_timeout.eq(1),
NextState("IDLE")
).Else(
If(buffer_space_not,
self.cri.o_buffer_space_valid.eq(1),
NextState("IDLE")
),
)
)
# RX FSM
rx_fsm = ClockDomainsRenamer("rtio_rx")(FSM(reset_state="INPUT"))
self.submodules += rx_fsm
ongoing_packet_next = Signal()
ongoing_packet = Signal()
self.sync.rtio_rx += ongoing_packet.eq(ongoing_packet_next)
rx_fsm.act("INPUT",
If(rx_dp.frame_r,
rx_dp.packet_buffer_load.eq(1),
If(rx_dp.packet_last,
Case(rx_dp.packet_type, {
rx_plm.types["buffer_space_reply"]: NextState("BUFFER_SPACE"),
"default": self.err_unknown_packet_type.eq(1)
})
).Else(
ongoing_packet_next.eq(1)
)
),
If(~rx_dp.frame_r & ongoing_packet,
self.err_packet_truncated.eq(1)
)
)
rx_fsm.act("BUFFER_SPACE",
rx_buffer_space_not.eq(1),
rx_buffer_space.eq(rx_dp.packet_as["buffer_space_reply"].space),
NextState("INPUT")
)

2
artiq/gateware/drtio/rt_serializer.py
View File

@ -53,7 +53,7 @@ def get_m2s_layouts(alignment):
("address", 16),
("extra_data_cnt", 8),
("short_data", short_data_len))
plm.add_type("buffer_space_request")
plm.add_type("buffer_space_request", ("destination", 8))
plm.add_type("read_request", ("channel", 16), ("timeout", 64))

36
artiq/gateware/test/drtio/test_rt_packet_repeater.py
View File

@ -60,3 +60,39 @@ class TestRepeater(unittest.TestCase):
run_simulation(dut, [send(), pr.receive(receive)])
self.assertEqual(test_writes, received)
def test_buffer_space(self):
for nwords in range(1, 8):
pt, pr, dut = create_dut(nwords)
def send_requests():
for i in range(10):
yield dut.cri.chan_sel.eq(i << 16)
yield dut.cri.cmd.eq(cri.commands["get_buffer_space"])
yield
yield dut.cri.cmd.eq(cri.commands["nop"])
yield
while not (yield dut.cri.o_buffer_space_valid):
yield
buffer_space = yield dut.cri.o_buffer_space
self.assertEqual(buffer_space, 2*i)
current_request = None
@passive
def send_replies():
nonlocal current_request
while True:
while current_request is None:
yield
yield from pt.send("buffer_space_reply", space=2*current_request)
current_request = None
def receive(packet_type, field_dict, trailer):
nonlocal current_request
self.assertEqual(packet_type, "buffer_space_request")
self.assertEqual(trailer, [])
self.assertEqual(current_request, None)
current_request = field_dict["destination"]
run_simulation(dut, [send_requests(), send_replies(), pr.receive(receive)])