drtio: support PHY latency compensation

This commit is contained in:
Sebastien Bourdeauducq 2017-03-14 00:01:38 +08:00
parent 497c795d8c
commit 95ede18809
1 changed files with 18 additions and 4 deletions

View File

@ -35,6 +35,13 @@ class IOS(Module):
fine_ts_width = rtlink.get_fine_ts_width(interface)
assert fine_ts_width <= max_fine_ts_width
# latency compensation
if interface.delay:
tsc_comp = Signal.like(self.tsc)
self.sync.rtio += tsc_comp.eq(self.tsc - interface.delay + 1)
else:
tsc_comp = self.tsc
# FIFO
ev_layout = []
if data_width:
@ -69,7 +76,7 @@ class IOS(Module):
rt_packet.write_underflow.eq(0)),
If(fifo.we,
If(~fifo.writable, rt_packet.write_overflow.eq(1)),
If(rt_packet.write_timestamp[max_fine_ts_width:] < (self.tsc + 4),
If(rt_packet.write_timestamp[max_fine_ts_width:] < (tsc_comp + 4),
rt_packet.write_underflow.eq(1)
)
)
@ -86,7 +93,7 @@ class IOS(Module):
fifo.re.eq(0),
interface.stb.eq(0),
If(fifo.readable &
(fifo_out.timestamp[fine_ts_width:] == self.tsc),
(fifo_out.timestamp[fine_ts_width:] == tsc_comp),
fifo.re.eq(1),
interface.stb.eq(1)
)
@ -108,6 +115,13 @@ class IOS(Module):
selected = Signal()
self.comb += selected.eq(rt_packet.read_channel == n)
# latency compensation
if interface.delay:
tsc_comp = Signal.like(self.tsc)
self.sync.rtio += tsc_comp.eq(self.tsc - interface.delay + 1)
else:
tsc_comp = self.tsc
# FIFO
ev_layout = []
if data_width:
@ -130,9 +144,9 @@ class IOS(Module):
self.comb += fifo_in.data.eq(interface.data)
if interface.timestamped:
if fine_ts_width:
full_ts = Cat(interface.fine_ts, self.tsc)
full_ts = Cat(interface.fine_ts, tsc_comp)
else:
full_ts = self.tsc
full_ts = tsc_comp
self.comb += fifo_in.timestamp.eq(full_ts)
self.comb += fifo.we.eq(interface.stb)