artiq/artiq/gateware/drtio/rt_serializer.py

198 lines
6.0 KiB
Python

"""Serializer for real-time data, common to satellite and master"""
from types import SimpleNamespace
from migen import *
__all__ = ["ReceiveDatapath", "TransmitDatapath",
"get_m2s_layouts", "get_s2m_layouts"]
def layout_len(l):
return sum(e[1] for e in l)
class PacketLayoutManager:
def __init__(self, alignment):
self.alignment = alignment
self.layouts = dict()
self.types = dict()
self.type_names = dict()
def add_type(self, name, *fields, pad=True):
type_n = len(self.types)
self.types[name] = type_n
self.type_names[type_n] = name
layout = [("ty", 8)] + list(fields)
misalignment = layout_len(layout) % self.alignment
if misalignment:
layout.append(("packet_pad", self.alignment - misalignment))
self.layouts[name] = layout
def field_length(self, type_name, field_name):
layout = self.layouts[type_name]
for name, length in layout:
if name == field_name:
return length
raise KeyError
def get_m2s_layouts(alignment):
if alignment > 128:
short_data_len = alignment - 128 + 16
else:
short_data_len = 16
plm = PacketLayoutManager(alignment)
plm.add_type("echo_request")
plm.add_type("set_time", ("timestamp", 64))
plm.add_type("write", ("timestamp", 64),
("chan_sel", 24),
("address", 8),
("extra_data_cnt", 8),
("short_data", short_data_len))
plm.add_type("buffer_space_request", ("destination", 8))
plm.add_type("read_request", ("chan_sel", 24), ("timeout", 64))
return plm
def get_s2m_layouts(alignment):
plm = PacketLayoutManager(alignment)
plm.add_type("echo_reply")
plm.add_type("buffer_space_reply", ("space", 16))
plm.add_type("read_reply", ("timestamp", 64), ("data", 32))
plm.add_type("read_reply_noevent", ("overflow", 1)) # overflow=0→timeout
return plm
class ReceiveDatapath(Module):
def __init__(self, frame, data, plm):
ws = len(data)
# control
self.packet_buffer_load = Signal()
# outputs
self.frame_r = Signal()
self.data_r = Signal(ws)
self.packet_type = Signal(8)
self.packet_last = Signal()
self.packet_as = dict()
# # #
# input pipeline stage - determine packet length based on type
lastword_per_type = [layout_len(plm.layouts[plm.type_names[i]])//ws - 1
for i in range(len(plm.layouts))]
packet_last_n = Signal(max=max(lastword_per_type)+1)
self.sync += [
self.frame_r.eq(frame),
self.data_r.eq(data),
If(frame & ~self.frame_r,
self.packet_type.eq(data[:8]),
packet_last_n.eq(Array(lastword_per_type)[data[:8]])
)
]
# bufferize packet
packet_buffer = Signal(max(layout_len(l)
for l in plm.layouts.values()))
w_in_packet = len(packet_buffer)//ws
packet_buffer_count = Signal(max=w_in_packet+1)
self.sync += \
If(self.packet_buffer_load,
Case(packet_buffer_count,
{i: packet_buffer[i*ws:(i+1)*ws].eq(self.data_r)
for i in range(w_in_packet)}),
packet_buffer_count.eq(packet_buffer_count + 1)
).Else(
packet_buffer_count.eq(0)
)
self.comb += self.packet_last.eq(packet_buffer_count == packet_last_n)
# dissect packet
for name, layout in plm.layouts.items():
fields = SimpleNamespace()
idx = 0
for field_name, field_size in layout:
setattr(fields, field_name, packet_buffer[idx:idx+field_size])
idx += field_size
self.packet_as[name] = fields
class TransmitDatapath(Module):
def __init__(self, frame, data, plm):
ws = len(data)
assert ws % 8 == 0
self.ws = ws
self.plm = plm
self.packet_buffer = Signal(max(layout_len(l)
for l in plm.layouts.values()))
w_in_packet = len(self.packet_buffer)//ws
self.packet_last_n = Signal(max=max(w_in_packet, 2))
self.packet_stb = Signal()
self.packet_last = Signal()
self.raw_stb = Signal()
self.raw_data = Signal(ws)
# # #
self.sync += frame.eq(0)
if w_in_packet > 1:
packet_buffer_count = Signal(max=w_in_packet)
self.comb += self.packet_last.eq(packet_buffer_count == self.packet_last_n)
self.sync += [
packet_buffer_count.eq(0),
If(self.packet_stb,
frame.eq(1),
Case(packet_buffer_count,
{i: data.eq(self.packet_buffer[i*ws:(i+1)*ws])
for i in range(w_in_packet)}),
packet_buffer_count.eq(packet_buffer_count + 1)
)
]
else:
self.comb += self.packet_last.eq(1)
self.sync += \
If(self.packet_stb,
frame.eq(1),
data.eq(self.packet_buffer)
)
self.sync += [
If(self.raw_stb,
frame.eq(1),
data.eq(self.raw_data)
)
]
def send(self, ty, **kwargs):
idx = 8
value = self.plm.types[ty]
for field_name, field_size in self.plm.layouts[ty][1:]:
try:
fvalue = kwargs[field_name]
del kwargs[field_name]
except KeyError:
fvalue = 0
value = value | (fvalue << idx)
idx += field_size
if kwargs:
raise ValueError
return [
self.packet_stb.eq(1),
self.packet_buffer.eq(value),
self.packet_last_n.eq(idx//self.ws-1)
]