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gateware/rtio: factor _BlindTransfer

This commit is contained in:
Robert Jördens 2016-03-09 19:04:06 +01:00
parent 10a09122ea
commit 107e5cfbd4
1 changed files with 30 additions and 24 deletions

View File

@ -54,6 +54,26 @@ class _RTIOCounter(Module):
self.comb += gt.i.eq(self.value_rtio), self.value_sys.eq(gt.o)
class _BlindTransfer(Module):
def __init__(self):
self.i = Signal()
self.o = Signal()
ps = PulseSynchronizer("rio", "rsys")
ps_ack = PulseSynchronizer("rsys", "rio")
self.submodules += ps, ps_ack
blind = Signal()
self.sync.rio += [
If(self.i, blind.eq(1)),
If(ps_ack.o, blind.eq(0))
]
self.comb += [
ps.i.eq(self.i & ~blind),
ps_ack.i.eq(ps.o),
self.o.eq(ps.o)
]
# CHOOSING A GUARD TIME
#
# The buffer must be transferred to the FIFO soon enough to account for:
@ -221,24 +241,17 @@ class _OutputManager(Module):
self.comb += fifo.re.eq(fifo.readable & (~dout_stb | dout_ack))
# FIFO read through buffer
# TODO: report error on stb & busy
self.comb += [
dout_ack.eq(
dout.timestamp[fine_ts_width:] == counter.value_rtio),
interface.stb.eq(dout_stb & dout_ack)
]
busy_sync = PulseSynchronizer("rio", "rsys")
busy_ack_sync = PulseSynchronizer("rsys", "rio")
self.submodules += busy_sync, busy_ack_sync
busy_blind = Signal()
self.comb += busy_sync.i.eq(interface.stb & interface.busy & ~busy_blind)
self.sync.rio += [
If(interface.stb & interface.busy, busy_blind.eq(1)),
If(busy_ack_sync.o, busy_blind.eq(0))
]
busy_transfer = _BlindTransfer()
self.submodules += busy_transfer
self.comb += [
busy_ack_sync.i.eq(busy_sync.o),
self.busy.eq(busy_sync.o)
busy_transfer.i.eq(interface.stb & interface.busy),
self.busy.eq(busy_transfer.o),
]
if data_width:
@ -263,7 +276,7 @@ class _InputManager(Module):
self.readable = Signal()
self.re = Signal()
self.overflow = Signal() # pulsed
# # #
@ -296,18 +309,11 @@ class _InputManager(Module):
fifo.re.eq(self.re)
]
overflow_sync = PulseSynchronizer("rio", "rsys")
overflow_ack_sync = PulseSynchronizer("rsys", "rio")
self.submodules += overflow_sync, overflow_ack_sync
overflow_blind = Signal()
self.comb += overflow_sync.i.eq(fifo.we & ~fifo.writable & ~overflow_blind)
self.sync.rio += [
If(fifo.we & ~fifo.writable, overflow_blind.eq(1)),
If(overflow_ack_sync.o, overflow_blind.eq(0))
]
overflow_transfer = _BlindTransfer()
self.submodules += overflow_transfer
self.comb += [
overflow_ack_sync.i.eq(overflow_sync.o),
self.overflow.eq(overflow_sync.o)
overflow_transfer.i.eq(fifo.we & ~fifo.writable),
self.overflow.eq(overflow_transfer.o),
]