From 4112e403de6350d67343475f0b367878c4ce5980 Mon Sep 17 00:00:00 2001 From: Sebastien Bourdeauducq Date: Tue, 26 Sep 2017 15:09:07 +0800 Subject: [PATCH] rtio/sed: latency compensation --- artiq/gateware/rtio/sed/core.py | 4 +- artiq/gateware/rtio/sed/lane_distributor.py | 62 +++++++++++++------ .../test/rtio/test_sed_lane_distributor.py | 3 +- 3 files changed, 47 insertions(+), 22 deletions(-) diff --git a/artiq/gateware/rtio/sed/core.py b/artiq/gateware/rtio/sed/core.py index df4e61b69..472eda626 100644 --- a/artiq/gateware/rtio/sed/core.py +++ b/artiq/gateware/rtio/sed/core.py @@ -31,7 +31,9 @@ class SED(Module): self.submodules.lane_dist = lane_dist_cdr( LaneDistributor(lane_count, seqn_width, - layouts.fifo_payload(channels), glbl_fine_ts_width, + layouts.fifo_payload(channels), + [channel.interface.o.delay for channel in channels], + glbl_fine_ts_width, enable_spread=enable_spread, quash_channels=quash_channels, interface=interface)) diff --git a/artiq/gateware/rtio/sed/lane_distributor.py b/artiq/gateware/rtio/sed/lane_distributor.py index 436e59695..c0a7e6857 100644 --- a/artiq/gateware/rtio/sed/lane_distributor.py +++ b/artiq/gateware/rtio/sed/lane_distributor.py @@ -13,7 +13,8 @@ __all__ = ["LaneDistributor"] # 3. check status class LaneDistributor(Module): - def __init__(self, lane_count, seqn_width, layout_payload, glbl_fine_ts_width, + def __init__(self, lane_count, seqn_width, layout_payload, + compensation, glbl_fine_ts_width, enable_spread=True, quash_channels=[], interface=None): if lane_count & (lane_count - 1): raise NotImplementedError("lane count must be a power of 2") @@ -53,27 +54,20 @@ class LaneDistributor(Module): self.comb += lio.payload.data.eq(self.cri.o_data) # when timestamp and channel arrive in cycle #1, prepare computations - coarse_timestamp = Signal(64-glbl_fine_ts_width) + us_timestamp_width = 64 - glbl_fine_ts_width + coarse_timestamp = Signal(us_timestamp_width) self.comb += coarse_timestamp.eq(self.cri.timestamp[glbl_fine_ts_width:]) - timestamp_above_min = Signal() - timestamp_above_laneA_min = Signal() - timestamp_above_laneB_min = Signal() - force_laneB = Signal() - use_laneB = Signal() - use_lanen = Signal(max=lane_count) + min_minus_timestamp = Signal((us_timestamp_width + 1, True)) + laneAmin_minus_timestamp = Signal((us_timestamp_width + 1, True)) + laneBmin_minus_timestamp = Signal((us_timestamp_width + 1, True)) + last_minus_timestamp = Signal((us_timestamp_width + 1, True)) current_lane_plus_one = Signal(max=lane_count) self.comb += current_lane_plus_one.eq(current_lane + 1) self.sync += [ - timestamp_above_min.eq(coarse_timestamp > self.minimum_coarse_timestamp), - timestamp_above_laneA_min.eq(coarse_timestamp > last_lane_coarse_timestamps[current_lane]), - timestamp_above_laneB_min.eq(coarse_timestamp > last_lane_coarse_timestamps[current_lane_plus_one]), - If(force_laneB | (coarse_timestamp <= last_coarse_timestamp), - use_lanen.eq(current_lane + 1), - use_laneB.eq(1) - ).Else( - use_lanen.eq(current_lane), - use_laneB.eq(0) - ) + min_minus_timestamp.eq(self.minimum_coarse_timestamp - coarse_timestamp), + laneAmin_minus_timestamp.eq(last_lane_coarse_timestamps[current_lane] - coarse_timestamp), + laneBmin_minus_timestamp.eq(last_lane_coarse_timestamps[current_lane_plus_one] - coarse_timestamp), + last_minus_timestamp.eq(last_coarse_timestamp - coarse_timestamp) ] quash = Signal() @@ -81,12 +75,36 @@ class LaneDistributor(Module): for channel in quash_channels: self.sync += If(self.cri.chan_sel[:16] == channel, quash.eq(1)) + latency_compensation = Memory(14, len(compensation), init=compensation) + latency_compensation_port = latency_compensation.get_port() + self.specials += latency_compensation, latency_compensation_port + self.comb += latency_compensation_port.adr.eq(self.cri.chan_sel[:16]) + # cycle #2, write + compensation = latency_compensation_port.dat_r + timestamp_above_min = Signal() + timestamp_above_laneA_min = Signal() + timestamp_above_laneB_min = Signal() timestamp_above_lane_min = Signal() + force_laneB = Signal() + use_laneB = Signal() + use_lanen = Signal(max=lane_count) + do_write = Signal() do_underflow = Signal() do_sequence_error = Signal() self.comb += [ + timestamp_above_min.eq(min_minus_timestamp - compensation < 0), + timestamp_above_laneA_min.eq(laneAmin_minus_timestamp - compensation < 0), + timestamp_above_laneB_min.eq(laneBmin_minus_timestamp - compensation < 0), + If(force_laneB | (last_minus_timestamp - compensation >= 0), + use_lanen.eq(current_lane + 1), + use_laneB.eq(1) + ).Else( + use_lanen.eq(current_lane), + use_laneB.eq(0) + ), + timestamp_above_lane_min.eq(Mux(use_laneB, timestamp_above_laneB_min, timestamp_above_laneA_min)), If(~quash, do_write.eq((self.cri.cmd == cri.commands["write"]) & timestamp_above_min & timestamp_above_lane_min), @@ -95,14 +113,18 @@ class LaneDistributor(Module): ), Array(lio.we for lio in self.output)[use_lanen].eq(do_write) ] + compensated_timestamp = Signal(64) + self.comb += compensated_timestamp.eq(self.cri.timestamp + (compensation << glbl_fine_ts_width)) self.sync += [ If(do_write, If(use_laneB, current_lane.eq(current_lane + 1)), - last_coarse_timestamp.eq(coarse_timestamp), - last_lane_coarse_timestamps[use_lanen].eq(coarse_timestamp), + last_coarse_timestamp.eq(compensated_timestamp[glbl_fine_ts_width:]), + last_lane_coarse_timestamps[use_lanen].eq(compensated_timestamp[glbl_fine_ts_width:]), seqn.eq(seqn + 1), ) ] + for lio in self.output: + self.comb += lio.payload.timestamp.eq(compensated_timestamp) # cycle #3, read status current_lane_writable = Signal() diff --git a/artiq/gateware/test/rtio/test_sed_lane_distributor.py b/artiq/gateware/test/rtio/test_sed_lane_distributor.py index 4c57bc9c8..db57ae6cd 100644 --- a/artiq/gateware/test/rtio/test_sed_lane_distributor.py +++ b/artiq/gateware/test/rtio/test_sed_lane_distributor.py @@ -10,7 +10,8 @@ LANE_COUNT = 8 def simulate(input_events, wait=True): - dut = lane_distributor.LaneDistributor(LANE_COUNT, 8, [("channel", 8), ("timestamp", 32)], 3) + dut = lane_distributor.LaneDistributor(LANE_COUNT, 8, [("channel", 8), ("timestamp", 32)], + [0]*256, 3) output = [] access_results = []