artiq/soc/artiqlib/rtio/__init__.py

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from migen.fhdl.std import *
from migen.bank.description import *
from migen.genlib.fifo import SyncFIFOBuffered
from migen.genlib.cdc import MultiReg
class RTIOBankO(Module):
def __init__(self, channels, counter_width, fifo_depth):
self.sel = Signal(max=len(channels))
self.timestamp = Signal(counter_width)
self.value = Signal()
self.writable = Signal()
self.we = Signal()
self.underflow = Signal()
self.level = Signal(bits_for(fifo_depth))
###
counter = Signal(counter_width)
self.sync += [
counter.eq(counter + 1),
If(self.we & self.writable,
If(self.timestamp < counter + 2, self.underflow.eq(1))
)
]
fifos = []
for n, channel in enumerate(channels):
fifo = SyncFIFOBuffered([
("timestamp", counter_width), ("value", 1)],
fifo_depth)
self.submodules += fifo
fifos.append(fifo)
# FIFO write
self.comb += [
fifo.din.timestamp.eq(self.timestamp),
fifo.din.value.eq(self.value),
fifo.we.eq(self.we & (self.sel == n))
]
# FIFO read
time_hit = Signal()
self.comb += [
time_hit.eq(fifo.readable &
(fifo.dout.timestamp == counter)),
fifo.re.eq(time_hit)
]
self.sync += If(time_hit, channel.eq(fifo.dout.value))
selfifo = Array(fifos)[self.sel]
self.comb += self.writable.eq(selfifo.writable), self.level.eq(selfifo.level)
class RTIO(Module, AutoCSR):
def __init__(self, channels, counter_width=32, ofifo_depth=8, ififo_depth=8):
self.submodules.bank_o = InsertReset(RTIOBankO(channels, counter_width, ofifo_depth))
self._r_reset = CSRStorage(reset=1)
self._r_chan_sel = CSRStorage(flen(self.bank_o.sel))
self._r_o_timestamp = CSRStorage(counter_width)
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self._r_o_value = CSRStorage()
self._r_o_writable = CSRStatus()
self._r_o_we = CSR()
self._r_o_underflow = CSRStatus()
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self._r_o_level = CSRStatus(bits_for(ofifo_depth))
self.comb += [
self.bank_o.reset.eq(self._r_reset.storage),
self.bank_o.sel.eq(self._r_chan_sel.storage),
self.bank_o.timestamp.eq(self._r_o_timestamp.storage),
self.bank_o.value.eq(self._r_o_value.storage),
self._r_o_writable.status.eq(self.bank_o.writable),
self.bank_o.we.eq(self._r_o_we.re),
self._r_o_underflow.status.eq(self.bank_o.underflow),
self._r_o_level.status.eq(self.bank_o.level)
]