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drtio: add RT write controller

This commit is contained in:
Sebastien Bourdeauducq 2016-10-24 19:50:13 +08:00
parent 83bec06226
commit 7dd6eb2f5e
2 changed files with 164 additions and 1 deletions

View File

@ -2,7 +2,7 @@ from types import SimpleNamespace
from migen import *
from artiq.gateware.drtio import link_layer, rt_packets, iot
from artiq.gateware.drtio import link_layer, rt_packets, iot, bus_interface
class DRTIOSatellite(Module):
@ -53,3 +53,7 @@ class DRTIOMaster(Module):
self.link_layer.rx_ready.eq(transceiver.rx_ready)
]
self.submodules.rt_packets = rt_packets.RTPacketMaster(self.link_layer)
self.submodules.rt_controller = rt_controller.RTController(self.rt_packets)
def get_csrs(self):
return self.rt_controller.get_csrs()

View File

@ -0,0 +1,159 @@
from migen import *
from misoc.interconnect.csr import *
from artiq.gateware.rtio.cdc import RTIOCounter
class _KernelCSRs(AutoCSR):
def __init__(self):
# chan_sel must be written at least 1 cycle before we
# and held stable until the transaction is complete.
# timestamp must be written at least 1 cycle before we.
self.chan_sel = CSRStorage(16)
self.o_data = CSRStorage(64)
self.o_address = CSRStorage(16)
self.o_timestamp = CSRStorage(64)
self.o_we = CSR()
self.o_status = CSRStatus(3)
self.o_underflow_reset = CSR()
self.o_sequence_error_reset = CSR()
self.counter = CSRStatus(64)
self.counter_update = CSR()
self.tsc_correction = CSRStorage(64)
self.set_time = CSR()
self.underflow_margin = CSRStorage(16, reset=50)
self.get_fifo_space = CSR()
self.dbg_fifo_space = CSRStatus(16)
self.dbg_last_timestamp = CSRStatus(64)
self.reset_channel_status = CSR()
class RTController(Module):
def __init__(self, rt_packets, channel_count=1024):
self.kcsrs = _KernelCSRs()
self.submodules.counter = RTIOCounter(64)
self.sync += If(self.kcsrs.counter_update.re,
self.kcsrs.counter.status.eq(self.counter.value_sys))
tsc_correction = Signal(64)
self.specials += MultiReg(self.tsc_correction.storage, tsc_correction)
self.comb += [
rt_packets.tsc_value.eq(
self.counter.value_rtio + tsc_correction),
self.set_time.value.eq(rt_packets.set_time_stb)
]
self.sync += [
If(rt_packets.set_time_ack, rt_packets.set_time_stb.eq(0)),
If(self.set_time_stb.re, rt_packets.set_time_stb.eq(1))
]
fifo_spaces_mem = Memory(16, channel_count)
fifo_spaces = fifo_spaces_mem.get_port(write_capable=True)
self.specials += fifo_spaces_mem, fifo_spaces
last_timestamps_mem = Memory(64, channel_count)
last_timestamps = last_timestamps_mem.get_port(write_capable=True)
self.specials += last_timestamps_mem, last_timestamps
rt_packets_fifo_request = Signal()
self.comb += [
fifo_spaces.adr.eq(self.kcsrs.chan_sel.storage),
last_timestamps.adr.eq(self.kcsrs.chan_sel.storage),
last_timestamps.dat_w.eq(self.kcsrs.timestamp.storage),
rt_packets.write_channel.eq(self.kcsrs.chan_sel.storage),
rt_packets.write_address.eq(self.kcsrs.o_address.storage),
rt_packets.write_data.eq(self.kcsrs.o_data.storage),
If(rt_packets_fifo_request,
rt_packets.write_timestamp.eq(0xffff000000000000)
).Else(
rt_packets.write_timestamp.eq(self.o_timestamp.storage)
)
]
fsm = FSM()
self.submodules += fsm
status_wait = Signal()
status_underflow = Signal()
status_sequence_error = Signal()
self.comb += self.kcsrs.o_status.status.eq(Cat(
status_wait, status_underflow, status_sequence_error))
# TODO: collision, replace, busy
cond_sequence_error = self.o_timestamp.storage < last_timestamps.dat_r
cond_underflow = (self.o_timestamp.storage - self.kcsrs.underflow_margin.storage
< self.counter.value_sys)
cond_fifo_emptied = ((last_timestamps.dat_r
< self.counter.value_sys - self.kcsrs.underflow_margin.storage)
& (last_timestamps.dat_r != 0))
fsm.act("IDLE",
If(self.o_we.re,
If(cond_sequence_error,
sequence_error_set.eq(1)
).Elif(cond_underflow,
underflow_set.eq(1)
).Else(
NextState("WRITE")
)
),
If(self.get_fifo_space.re,
NextState("GET_FIFO_SPACE")
)
)
fsm.act("WRITE",
status_wait.eq(1),
rt_packets.write_stb.eq(1),
If(rt_packets.write_ack,
fifo_spaces.we.eq(1),
If(cond_fifo_emptied,
fifo_spaces.dat_w.eq(1),
).Else(
fifo_spaces.dat_w.eq(fifo_spaces.dat_r - 1)
),
last_timestamps.we.eq(1),
If(fifo_spaces.dat_r <= 1,
NextState("GET_FIFO_SPACE")
).Else(
NextState("IDLE")
)
)
)
fsm.act("GET_FIFO_SPACE",
status_wait.eq(1),
rt_packets_fifo_request.eq(1),
rt_packets.write_stb.eq(1),
If(rt_packets.write_ack,
NextState("GET_FIFO_SPACE_REPLY")
)
)
fsm.act("GET_FIFO_SPACE_REPLY",
status_wait.eq(1),
fifo_spaces.dat_w.eq(rt_packets.fifo_space),
fifo_spaces.we.eq(1),
fifo_space_not_ack.eq(1),
If(rt_packets.fifo_space_not,
If(rt_packets.fifo_spaces > 0,
NextState("IDLE")
).Else(
NextState("GET_FIFO_SPACE")
)
)
)
self.comb += [
self.kcsrs.dbg_fifo_space.status.eq(fifo_spaces.dat_r),
self.kcsrs.dbg_last_timestamp.status.eq(last_timestamps.dat_r),
If(self.kcsrs.reset_channel_status.re,
fifo_spaces.dat_w.eq(0),
fifo_spaces.we.eq(1),
last_timestamps.dat_w.eq(0),
last_timestamps.we.eq(1)
)
]
def get_csrs(self):
return self.kcsrs.get_csrs()