drtio: RX clock alignment and ready

This commit is contained in:
Sebastien Bourdeauducq 2016-10-15 18:36:27 +08:00
parent 08e4aa3e3f
commit 03d3a85e75
3 changed files with 44 additions and 10 deletions

View File

@ -9,6 +9,11 @@ class DRTIOSatellite(Module):
def __init__(self, transceiver, rx_synchronizer, channels, fine_ts_width=3, full_ts_width=63):
self.submodules.link_layer = link_layer.LinkLayer(
transceiver.encoder, transceiver.decoders)
self.comb += [
transceiver.rx_reset.eq(self.link_layer.rx_reset),
self.link_layer.rx_ready.eq(transceiver.rx_ready)
]
link_layer_sync = SimpleNamespace(
tx_aux_frame=self.link_layer.tx.aux_frame,
tx_aux_data=self.link_layer.tx_aux_data,
@ -24,6 +29,7 @@ class DRTIOSatellite(Module):
)
self.submodules.rt_packets = ClockDomainsRenamer("rtio")(
rt_packets.RTPacketSatellite(link_layer_sync))
self.submodules.iot = ClockDomainsRenamer("rtio")(
iot.IOT(self.rt_packets, channels, fine_ts_width, full_ts_width))

View File

@ -164,7 +164,15 @@ class GTX_1000BASE_BX10(Module):
self.decoders[0].input.eq(rxdata[:10]),
self.decoders[1].input.eq(rxdata[10:])
]
# TODO: clock aligner, reset/ready
clock_aligner = BruteforceClockAligner(0b0011111000, 62.5e6)
self.submodules += clock_aligner
self.comb += [
clock_aligner.rxdata.eq(rxdata),
rx_init.restart.eq(clock_aligner.restart),
clock_aligner.reset.eq(self.rx_reset),
self.rx_ready.eq(clock_aligner.ready)
]
class RXSynchronizer(Module):

View File

@ -131,21 +131,26 @@ class GTXInit(Module):
# Those design flaws make RXSLIDE_MODE=PMA yet another broken and useless
# transceiver "feature".
class BruteforceClockAligner(Module):
def __init__(self, comma, sys_clk_freq, check_period=6e-3):
def __init__(self, comma, rtio_clk_freq, check_period=6e-3, ready_time=50e-3):
self.rxdata = Signal(20)
self.restart = Signal()
check_max_val = ceil(check_period*sys_clk_freq)
self.reset = Signal()
self.ready = Signal()
check_max_val = ceil(check_period*rtio_clk_freq)
check_counter = Signal(max=check_max_val+1)
check = Signal()
self.sync += [
self.sync.rtio += [
check.eq(0),
If(~self.ready,
If(check_counter == 0,
check.eq(1),
check_counter.eq(check_max_val)
).Else(
check_counter.eq(check_counter-1)
)
)
]
comma_n = ~comma & 0b1111111111
@ -154,7 +159,7 @@ class BruteforceClockAligner(Module):
self.specials += MultiReg(comma_seen_rxclk, comma_seen)
comma_seen_reset = PulseSynchronizer("sys", "rx")
self.submodules += comma_seen_reset
self.sync.rx += \
self.sync.rtio_rx += \
If(comma_seen_reset.o,
comma_seen_rxclk.eq(0)
).Elif((self.rxdata[:10] == comma) | (self.rxdata[:10] == comma_n),
@ -166,3 +171,18 @@ class BruteforceClockAligner(Module):
If(~comma_seen, self.restart.eq(1)),
comma_seen_reset.i.eq(1)
)
ready_counts = ceil(ready_time/check_period)
assert ready_counts > 1
ready_counter = Signal(max=ready_counts+1, reset=ready_counts)
self.sync.rtio += [
If(check,
If(comma_seen,
If(ready_counter != 0, ready_counter.eq(ready_counter-1))
).Else(
ready_counter.eq(ready_counts)
)
),
If(self.reset, ready_counter.eq(ready_counts))
]
self.comb += self.ready.eq(ready_counter == 0)