def build_param_store(self, m):
# Create memory for post process params
# Use SinglePortMemory here?
param_mem = Memory(width=POST_PROCESS_PARAMS_WIDTH,
depth=Constants.MAX_CHANNEL_DEPTH)
m.submodules['param_rp'] = rp = param_mem.read_port(transparent=False)
m.submodules['param_wp'] = wp = param_mem.write_port()
# Configure param writer
m.submodules['param_writer'] = pw = ParamWriter()
m.d.comb += connect(self.post_process_params, pw.input_data)
m.d.comb += [
pw.reset.eq(self.reset),
wp.en.eq(pw.mem_we),
wp.addr.eq(pw.mem_addr),
wp.data.eq(pw.mem_data),
]
# Configure param reader
m.submodules['param_reader'] = reader = ReadingProducer()
repeats = Mux(self.config.mode, Constants.SYS_ARRAY_HEIGHT,
Constants.SYS_ARRAY_HEIGHT // 2)
m.d.comb += [
# Reset reader whenever new parameters are written
reader.reset.eq(pw.input_data.is_transferring()),
reader.sizes.depth.eq(self.config.output_channel_depth),
reader.sizes.repeats.eq(repeats),
rp.addr.eq(reader.mem_addr),
reader.mem_data.eq(rp.data),
]
return reader.output_data
def elab(self, m):
mem = Memory(width=self.width, depth=self.depth, simulate=self.is_sim)
m.submodules['wp'] = wp = mem.write_port()
m.submodules['rp'] = rp = mem.read_port(transparent=False)
m.d.comb += [
wp.en.eq(self.w_en),
wp.addr.eq(self.w_addr),
wp.data.eq(self.w_data),
rp.en.eq(1),
rp.addr.eq(self.r_addr),
self.r_data.eq(rp.data),
]
def elab(self, m):
memory = Memory(width=self._data_width, depth=self._depth)
m.submodules.rp = rp = memory.read_port(transparent=False)
m.submodules.wp = wp = memory.write_port()
m.d.comb += [
wp.en.eq(self.write_enable),
rp.en.eq(~self.write_enable),
wp.addr.eq(self.write_addr),
wp.data.eq(self.write_data),
rp.addr.eq(self.read_addr),
self.read_data.eq(rp.data)
]
def elab(self, m: Module):
rp_data = []
for i in range(4):
mem = Memory(depth=self._depth // 4, width=32)
# Set up read port
m.submodules[f'rp_{i}'] = rp = mem.read_port(transparent=False)
rp_data.append(rp.data)
m.d.comb += rp.addr.eq(self.read_addr)
m.d.comb += rp.en.eq(~self.write_enable)
# Set up write port
m.submodules[f'wp_{i}'] = wp = mem.write_port()
m.d.comb += wp.addr.eq(self.write_addr[2:])
m.d.comb += wp.data.eq(self.write_data)
m.d.comb += wp.en.eq(self.write_enable
& (i == self.write_addr[:2]))
# Assemble all of the read port outputs into one, 128bit wide signal
m.d.comb += self.read_data.eq(Cat(rp_data))
class USBAnalyzer(Elaboratable):
""" Core USB analyzer; backed by a small ringbuffer in FPGA block RAM.
If you're looking to instantiate a full analyzer, you'll probably want to grab
one of the DRAM-based ringbuffer variants (which are currently forthcoming).
If you're looking to use this with a ULPI PHY, rather than the FPGA-convenient UTMI interface,
grab the UTMITranslator from `luna.gateware.interface.ulpi`.
Attributes
----------
stream: StreamInterface(), output stream
Stream that carries USB analyzer data.
idle: Signal(), output
Asserted iff the analyzer is not currently receiving data.
overrun: Signal(), output
Asserted iff the analyzer has received more data than it can store in its internal buffer.
Occurs if :attr:``stream`` is not being read quickly enough.
capturing: Signal(), output
Asserted iff the analyzer is currently capturing a packet.
Parameters
----------
utmi_interface: UTMIInterface()
The UTMI interface that carries the data to be analyzed.
mem_depth: int, default=8192
The depth of the analyzer's local ringbuffer, in bytes.
Must be a power of 2.
"""
# Current, we'll provide a packet header of 16 bits.
HEADER_SIZE_BITS = 16
HEADER_SIZE_BYTES = HEADER_SIZE_BITS // 8
# Support a maximum payload size of 1024B, plus a 1-byte PID and a 2-byte CRC16.
MAX_PACKET_SIZE_BYTES = 1024 + 1 + 2
def __init__(self, *, utmi_interface, mem_depth=8192):
"""
Parameters:
utmi_interface -- A record or elaboratable that presents a UTMI interface.
"""
self.utmi = utmi_interface
assert (mem_depth % 2) == 0, "mem_depth must be a power of 2"
# Internal storage memory.
self.mem = Memory(width=8, depth=mem_depth, name="analysis_ringbuffer")
self.mem_size = mem_depth
#
# I/O port
#
self.stream = StreamInterface()
self.idle = Signal()
self.overrun = Signal()
self.capturing = Signal()
# Diagnostic I/O.
self.sampling = Signal()
def elaborate(self, platform):
m = Module()
# Memory read and write ports.
m.submodules.read = mem_read_port = self.mem.read_port(domain="usb")
m.submodules.write = mem_write_port = self.mem.write_port(domain="usb")
# Store the memory address of our active packet header, which will store
# packet metadata like the packet size.
header_location = Signal.like(mem_write_port.addr)
write_location = Signal.like(mem_write_port.addr)
# Read FIFO status.
read_location = Signal.like(mem_read_port.addr)
fifo_count = Signal.like(mem_read_port.addr, reset=0)
fifo_new_data = Signal()
# Current receive status.
packet_size = Signal(16)
#
# Read FIFO logic.
#
m.d.comb += [
# We have data ready whenever there's data in the FIFO.
self.stream.valid.eq((fifo_count != 0) & self.idle),
# Our data_out is always the output of our read port...
self.stream.payload.eq(mem_read_port.data),
self.sampling.eq(mem_write_port.en)
]
# Once our consumer has accepted our current data, move to the next address.
with m.If(self.stream.ready & self.stream.valid):
m.d.usb += read_location.eq(read_location + 1)
m.d.comb += mem_read_port.addr.eq(read_location + 1)
with m.Else():
m.d.comb += mem_read_port.addr.eq(read_location),
#
# FIFO count handling.
#
fifo_full = (fifo_count == self.mem_size)
data_pop = Signal()
data_push = Signal()
m.d.comb += [
data_pop.eq(self.stream.ready & self.stream.valid),
data_push.eq(fifo_new_data & ~fifo_full)
]
# If we have both a read and a write, don't update the count,
# as we've both added one and subtracted one.
with m.If(data_push & data_pop):
pass
# Otherwise, add when data's added, and subtract when data's removed.
with m.Elif(data_push):
m.d.usb += fifo_count.eq(fifo_count + 1)
with m.Elif(data_pop):
m.d.usb += fifo_count.eq(fifo_count - 1)
#
# Core analysis FSM.
#
with m.FSM(domain="usb") as f:
m.d.comb += [
self.idle.eq(f.ongoing("IDLE")),
self.overrun.eq(f.ongoing("OVERRUN")),
self.capturing.eq(f.ongoing("CAPTURE")),
]
# IDLE: wait for an active receive.
with m.State("IDLE"):
# Wait until a transmission is active.
# TODO: add triggering logic?
with m.If(self.utmi.rx_active):
m.next = "CAPTURE"
m.d.usb += [
header_location.eq(write_location),
write_location.eq(write_location +
self.HEADER_SIZE_BYTES),
packet_size.eq(0),
]
# Capture data until the packet is complete.
with m.State("CAPTURE"):
byte_received = self.utmi.rx_valid & self.utmi.rx_active
# Capture data whenever RxValid is asserted.
m.d.comb += [
mem_write_port.addr.eq(write_location),
mem_write_port.data.eq(self.utmi.rx_data),
mem_write_port.en.eq(byte_received),
fifo_new_data.eq(byte_received),
]
# Advance the write pointer each time we receive a bit.
with m.If(byte_received):
m.d.usb += [
write_location.eq(write_location + 1),
packet_size.eq(packet_size + 1)
]
# If this would be filling up our data memory,
# move to the OVERRUN state.
with m.If(fifo_count == self.mem_size - 1 -
self.HEADER_SIZE_BYTES):
m.next = "OVERRUN"
# If we've stopped receiving, move to the "finalize" state.
with m.If(~self.utmi.rx_active):
m.next = "EOP_1"
# Optimization: if we didn't receive any data, there's no need
# to create a packet. Clear our header from the FIFO and disarm.
with m.If(packet_size == 0):
m.next = "IDLE"
m.d.usb += [write_location.eq(header_location)]
with m.Else():
m.next = "EOP_1"
# EOP: handle the end of the relevant packet.
with m.State("EOP_1"):
# Now that we're done, add the header to the start of our packet.
# This will take two cycles, currently, as we're using a 2-byte header,
# but we only have an 8-bit write port.
m.d.comb += [
mem_write_port.addr.eq(header_location),
mem_write_port.data.eq(packet_size[8:16]),
mem_write_port.en.eq(1),
fifo_new_data.eq(1)
]
m.next = "EOP_2"
with m.State("EOP_2"):
# Add the second byte of our header.
# Note that, if this is an adjacent read, we should have
# just captured our packet header _during_ the stop turnaround.
m.d.comb += [
mem_write_port.addr.eq(header_location + 1),
mem_write_port.data.eq(packet_size[0:8]),
mem_write_port.en.eq(1),
fifo_new_data.eq(1)
]
m.next = "IDLE"
# BABBLE -- handles the case in which we've received a packet beyond
# the allowable size in the USB spec
with m.State("BABBLE"):
# Trap here, for now.
pass
with m.State("OVERRUN"):
# TODO: we should probably set an overrun flag and then emit an EOP, here?
pass
return m
def elaborate(self, platform):
self.m = m = Module()
comb = m.d.comb
sync = m.d.sync
# CPU units used.
logic = m.submodules.logic = LogicUnit()
adder = m.submodules.adder = AdderUnit()
shifter = m.submodules.shifter = ShifterUnit()
compare = m.submodules.compare = CompareUnit()
self.current_priv_mode = Signal(PrivModeBits,
reset=PrivModeBits.MACHINE)
csr_unit = self.csr_unit = m.submodules.csr_unit = CsrUnit(
# TODO does '==' below produces the same synth result as .all()?
in_machine_mode=self.current_priv_mode == PrivModeBits.MACHINE)
exception_unit = self.exception_unit = m.submodules.exception_unit = ExceptionUnit(
csr_unit=csr_unit, current_priv_mode=self.current_priv_mode)
arbiter = self.arbiter = m.submodules.arbiter = MemoryArbiter(
mem_config=self.mem_config,
with_addr_translation=True,
csr_unit=csr_unit, # SATP register
exception_unit=exception_unit, # current privilege mode
)
mem_unit = m.submodules.mem_unit = MemoryUnit(mem_port=arbiter.port(
priority=0))
ibus = arbiter.port(priority=2)
if self.with_debug:
m.submodules.debug = self.debug = DebugUnit(self)
self.debug_bus = arbiter.port(priority=1)
# Current decoding state signals.
instr = self.instr = Signal(32)
funct3 = self.funct3 = Signal(3)
funct7 = self.funct7 = Signal(7)
rd = self.rd = Signal(5)
rs1 = Signal(5)
rs2 = Signal(5)
rs1val = Signal(32)
rs2val = Signal(32)
rdval = Signal(32) # calculated by unit, stored to register file
imm = Signal(signed(12))
csr_idx = Signal(12)
uimm = Signal(20)
opcode = self.opcode = Signal(InstrType)
pc = self.pc = Signal(32, reset=CODE_START_ADDR)
# at most one active_unit at any time
active_unit = ActiveUnit()
# Register file. Contains two read ports (for rs1, rs2) and one write port.
regs = Memory(width=32, depth=32, init=self.reg_init)
reg_read_port1 = m.submodules.reg_read_port1 = regs.read_port()
reg_read_port2 = m.submodules.reg_read_port2 = regs.read_port()
reg_write_port = (self.reg_write_port
) = m.submodules.reg_write_port = regs.write_port()
# Timer management.
mtime = self.mtime = Signal(32)
sync += mtime.eq(mtime + 1)
comb += csr_unit.mtime.eq(mtime)
self.halt = Signal()
with m.If(csr_unit.mstatus.mie & csr_unit.mie.mtie):
with m.If(mtime == csr_unit.mtimecmp):
# 'halt' signal needs to be cleared when CPU jumps to trap handler.
sync += [
self.halt.eq(1),
]
comb += [
exception_unit.m_instruction.eq(instr),
exception_unit.m_pc.eq(pc),
# TODO more
]
# TODO
# DebugModule is able to read and write GPR values.
# if self.with_debug:
# comb += self.halt.eq(self.debug.HALT)
# else:
# comb += self.halt.eq(0)
# with m.If(self.halt):
# comb += [
# reg_read_port1.addr.eq(self.gprf_debug_addr),
# reg_write_port.addr.eq(self.gprf_debug_addr),
# reg_write_port.en.eq(self.gprf_debug_write_en)
# ]
# with m.If(self.gprf_debug_write_en):
# comb += reg_write_port.data.eq(self.gprf_debug_data)
# with m.Else():
# comb += self.gprf_debug_data.eq(reg_read_port1.data)
with m.If(0):
pass
with m.Else():
comb += [
reg_read_port1.addr.eq(rs1),
reg_read_port2.addr.eq(rs2),
reg_write_port.addr.eq(rd),
reg_write_port.data.eq(rdval),
# reg_write_port.en set later
rs1val.eq(reg_read_port1.data),
rs2val.eq(reg_read_port2.data),
]
comb += [
# following is not true for all instrutions, but in specific cases will be overwritten later
imm.eq(instr[20:32]),
csr_idx.eq(instr[20:32]),
uimm.eq(instr[12:]),
]
# drive input signals of actually used unit.
with m.If(active_unit.logic):
comb += [
logic.funct3.eq(funct3),
logic.src1.eq(rs1val),
logic.src2.eq(Mux(opcode == InstrType.OP_IMM, imm, rs2val)),
]
with m.Elif(active_unit.adder):
comb += [
adder.src1.eq(rs1val),
adder.src2.eq(Mux(opcode == InstrType.OP_IMM, imm, rs2val)),
]
with m.Elif(active_unit.shifter):
comb += [
shifter.funct3.eq(funct3),
shifter.funct7.eq(funct7),
shifter.src1.eq(rs1val),
shifter.shift.eq(
Mux(opcode == InstrType.OP_IMM, imm[0:5].as_unsigned(),
rs2val[0:5])),
]
with m.Elif(active_unit.mem_unit):
comb += [
mem_unit.en.eq(1),
mem_unit.funct3.eq(funct3),
mem_unit.src1.eq(rs1val),
mem_unit.src2.eq(rs2val),
mem_unit.store.eq(opcode == InstrType.STORE),
mem_unit.offset.eq(
Mux(opcode == InstrType.LOAD, imm, Cat(rd, imm[5:12]))),
]
with m.Elif(active_unit.compare):
comb += [
compare.funct3.eq(funct3),
# Compare Unit uses Adder for carry and overflow flags.
adder.src1.eq(rs1val),
adder.src2.eq(Mux(opcode == InstrType.OP_IMM, imm, rs2val)),
# adder.sub set somewhere below
]
with m.Elif(active_unit.branch):
comb += [
compare.funct3.eq(funct3),
# Compare Unit uses Adder for carry and overflow flags.
adder.src1.eq(rs1val),
adder.src2.eq(rs2val),
# adder.sub set somewhere below
]
with m.Elif(active_unit.csr):
comb += [
csr_unit.func3.eq(funct3),
csr_unit.csr_idx.eq(csr_idx),
csr_unit.rs1.eq(rs1),
csr_unit.rs1val.eq(rs1val),
csr_unit.rd.eq(rd),
csr_unit.en.eq(1),
]
comb += [
compare.negative.eq(adder.res[-1]),
compare.overflow.eq(adder.overflow),
compare.carry.eq(adder.carry),
compare.zero.eq(adder.res == 0),
]
# Decoding state (with redundancy - instr. type not known yet).
# We use 'ibus.read_data' instead of 'instr' (that is driven by sync domain)
# for getting registers to save 1 cycle.
comb += [
opcode.eq(instr[0:7]),
rd.eq(instr[7:12]),
funct3.eq(instr[12:15]),
rs1.eq(instr[15:20]),
rs2.eq(instr[20:25]),
funct7.eq(instr[25:32]),
]
def fetch_with_new_pc(pc: Signal):
m.next = "FETCH"
m.d.sync += active_unit.eq(0)
m.d.sync += self.pc.eq(pc)
def trap(cause: Optional[Union[TrapCause, IrqCause]], interrupt=False):
fetch_with_new_pc(Cat(Const(0, 2), self.csr_unit.mtvec.base))
if cause is None:
return
assert isinstance(cause, TrapCause) or isinstance(cause, IrqCause)
e = exception_unit
notifiers = e.irq_cause_map if interrupt else e.trap_cause_map
m.d.comb += notifiers[cause].eq(1)
self.fetch = Signal()
interconnect_error = Signal()
comb += interconnect_error.eq(exception_unit.m_store_error
| exception_unit.m_fetch_error
| exception_unit.m_load_error)
with m.FSM():
with m.State("FETCH"):
with m.If(self.halt):
sync += self.halt.eq(0)
trap(IrqCause.M_TIMER_INTERRUPT, interrupt=True)
with m.Else():
with m.If(pc & 0b11):
trap(TrapCause.FETCH_MISALIGNED)
with m.Else():
comb += [
ibus.en.eq(1),
ibus.store.eq(0),
ibus.addr.eq(pc),
ibus.mask.eq(0b1111),
ibus.is_fetch.eq(1),
]
with m.If(interconnect_error):
trap(cause=None)
with m.If(ibus.ack):
sync += [
instr.eq(ibus.read_data),
]
m.next = "DECODE"
with m.State("DECODE"):
comb += self.fetch.eq(
1
) # only for simulation, notify that 'instr' ready to use.
m.next = "EXECUTE"
# here, we have registers already fetched into rs1val, rs2val.
with m.If(instr & 0b11 != 0b11):
trap(TrapCause.ILLEGAL_INSTRUCTION)
with m.If(match_logic_unit(opcode, funct3, funct7)):
sync += [
active_unit.logic.eq(1),
]
with m.Elif(match_adder_unit(opcode, funct3, funct7)):
sync += [
active_unit.adder.eq(1),
adder.sub.eq((opcode == InstrType.ALU)
& (funct7 == Funct7.SUB)),
]
with m.Elif(match_shifter_unit(opcode, funct3, funct7)):
sync += [
active_unit.shifter.eq(1),
]
with m.Elif(match_loadstore_unit(opcode, funct3, funct7)):
sync += [
active_unit.mem_unit.eq(1),
]
with m.Elif(match_compare_unit(opcode, funct3, funct7)):
sync += [
active_unit.compare.eq(1),
adder.sub.eq(1),
]
with m.Elif(match_lui(opcode, funct3, funct7)):
sync += [
active_unit.lui.eq(1),
]
comb += [
reg_read_port1.addr.eq(rd),
# rd will be available in next cycle in rs1val
]
with m.Elif(match_auipc(opcode, funct3, funct7)):
sync += [
active_unit.auipc.eq(1),
]
with m.Elif(match_jal(opcode, funct3, funct7)):
sync += [
active_unit.jal.eq(1),
]
with m.Elif(match_jalr(opcode, funct3, funct7)):
sync += [
active_unit.jalr.eq(1),
]
with m.Elif(match_branch(opcode, funct3, funct7)):
sync += [
active_unit.branch.eq(1),
adder.sub.eq(1),
]
with m.Elif(match_csr(opcode, funct3, funct7)):
sync += [active_unit.csr.eq(1)]
with m.Elif(match_mret(opcode, funct3, funct7)):
sync += [active_unit.mret.eq(1)]
with m.Elif(match_sfence_vma(opcode, funct3, funct7)):
pass # sfence.vma
with m.Elif(opcode == 0b0001111):
pass # fence
with m.Else():
trap(TrapCause.ILLEGAL_INSTRUCTION)
with m.State("EXECUTE"):
with m.If(active_unit.logic):
sync += [
rdval.eq(logic.res),
]
with m.Elif(active_unit.adder):
sync += [
rdval.eq(adder.res),
]
with m.Elif(active_unit.shifter):
sync += [
rdval.eq(shifter.res),
]
with m.Elif(active_unit.mem_unit):
sync += [
rdval.eq(mem_unit.res),
]
with m.Elif(active_unit.compare):
sync += [
rdval.eq(compare.condition_met),
]
with m.Elif(active_unit.lui):
sync += [
rdval.eq(Cat(Const(0, 12), uimm)),
]
with m.Elif(active_unit.auipc):
sync += [
rdval.eq(pc + Cat(Const(0, 12), uimm)),
]
with m.Elif(active_unit.jal | active_unit.jalr):
sync += [
rdval.eq(pc + 4),
]
with m.Elif(active_unit.csr):
sync += [rdval.eq(csr_unit.rd_val)]
# control flow mux - all traps need to be here, otherwise it will overwrite m.next statement.
with m.If(active_unit.mem_unit):
with m.If(mem_unit.ack):
m.next = "WRITEBACK"
sync += active_unit.eq(0)
with m.Else():
m.next = "EXECUTE"
with m.If(interconnect_error):
# NOTE:
# the order of that 'If' is important.
# In case of error overwrite m.next above.
trap(cause=None)
with m.Elif(active_unit.csr):
with m.If(csr_unit.illegal_insn):
trap(TrapCause.ILLEGAL_INSTRUCTION)
with m.Else():
with m.If(csr_unit.vld):
m.next = "WRITEBACK"
sync += active_unit.eq(0)
with m.Else():
m.next = "EXECUTE"
with m.Elif(active_unit.mret):
comb += exception_unit.m_mret.eq(1)
fetch_with_new_pc(exception_unit.mepc)
with m.Else():
# all units not specified by default take 1 cycle
m.next = "WRITEBACK"
sync += active_unit.eq(0)
jal_offset = Signal(signed(21))
comb += jal_offset.eq(
Cat(
Const(0, 1),
instr[21:31],
instr[20],
instr[12:20],
instr[31],
).as_signed())
pc_addend = Signal(signed(32))
sync += pc_addend.eq(Mux(active_unit.jal, jal_offset, 4))
branch_addend = Signal(signed(13))
comb += branch_addend.eq(
Cat(
Const(0, 1),
instr[8:12],
instr[25:31],
instr[7],
instr[31],
).as_signed() # TODO is it ok that it's signed?
)
with m.If(active_unit.branch):
with m.If(compare.condition_met):
sync += pc_addend.eq(branch_addend)
new_pc = Signal(32)
is_jalr_latch = Signal() # that's bad workaround
with m.If(active_unit.jalr):
sync += is_jalr_latch.eq(1)
sync += new_pc.eq(rs1val.as_signed() + imm)
with m.State("WRITEBACK"):
with m.If(is_jalr_latch):
sync += pc.eq(new_pc)
with m.Else():
sync += pc.eq(pc + pc_addend)
sync += is_jalr_latch.eq(0)
# Here, rdval is already calculated. If neccessary, put it into register file.
should_write_rd = self.should_write_rd = Signal()
writeback = self.writeback = Signal()
# for riscv-dv simulation:
# detect that instruction does not perform register write to avoid infinite loop
# by checking writeback & should_write_rd
# TODO it will break for trap-causing instructions.
comb += writeback.eq(1)
comb += should_write_rd.eq(
reduce(
or_,
[
match_shifter_unit(opcode, funct3, funct7),
match_adder_unit(opcode, funct3, funct7),
match_logic_unit(opcode, funct3, funct7),
match_load(opcode, funct3, funct7),
match_compare_unit(opcode, funct3, funct7),
match_lui(opcode, funct3, funct7),
match_auipc(opcode, funct3, funct7),
match_jal(opcode, funct3, funct7),
match_jalr(opcode, funct3, funct7),
match_csr(opcode, funct3, funct7),
],
)
& (rd != 0))
with m.If(should_write_rd):
comb += reg_write_port.en.eq(True)
m.next = "FETCH"
return m
class ADATTransmitter(Elaboratable):
"""transmit ADAT from a multiplexed stream of eight audio channels
Parameters
----------
fifo_depth: capacity of the FIFO containing the ADAT frames to be transmitted
Attributes
----------
adat_out: Signal
the ADAT signal to be transmitted by the optical transmitter
This input is unused at the moment. Instead the caller needs to ensure
addr_in: Signal
contains the ADAT channel number (0-7) of the current sample to be written
into the currently assembled ADAT frame
sample_in: Signal
the 24 bit sample to be written into the channel slot given by addr_in
in the currently assembled ADAT frame. The samples need to be committed
in order of channel number (0-7)
user_data_in: Signal
the user data bits of the currently assembled frame. Will be committed,
when ``last_in`` is strobed high
valid_in: Signal
commits the data at sample_in into the currently assembled frame,
but only if ``ready_out`` is high
ready_out: Signal
outputs if there is space left in the transmit FIFO. It also will
prevent any samples to be committed into the currently assembled ADAT frame
last_in: Signal
needs to be strobed when the last sample has been committed into the currently
assembled ADAT frame. This will commit the user bits to the current ADAT frame
fifo_level_out: Signal
outputs the number of entries in the transmit FIFO
underflow_out: Signal
this underflow indicator will be strobed, when a new ADAT frame needs to be
transmitted but the transmit FIFO is empty. In this case, the last
ADAT frame will be transmitted again.
"""
def __init__(self, fifo_depth=9*4):
self._fifo_depth = fifo_depth
self.adat_out = Signal()
self.addr_in = Signal(3)
self.sample_in = Signal(24)
self.user_data_in = Signal(4)
self.valid_in = Signal()
self.ready_out = Signal()
self.last_in = Signal()
self.fifo_level_out = Signal(range(fifo_depth+1))
self.underflow_out = Signal()
self.mem = Memory(width=24, depth=8, name="sample_buffer")
@staticmethod
def chunks(lst: list, n: int):
"""Yield successive n-sized chunks from lst."""
for i in range(0, len(lst), n):
yield lst[i:i + n]
def elaborate(self, platform) -> Module:
m = Module()
sync = m.d.sync
adat = m.d.adat
comb = m.d.comb
samples_write_port = self.mem.write_port()
samples_read_port = self.mem.read_port(domain='comb')
m.submodules += [samples_write_port, samples_read_port]
# the highest bit in the FIFO marks a frame border
frame_border_flag = 24
m.submodules.transmit_fifo = transmit_fifo = AsyncFIFO(width=25, depth=self._fifo_depth, w_domain="sync", r_domain="adat")
# needed for output processing
m.submodules.nrzi_encoder = nrzi_encoder = NRZIEncoder()
transmitted_frame = Signal(30)
transmit_counter = Signal(5)
comb += [
self.ready_out .eq(transmit_fifo.w_rdy),
self.fifo_level_out .eq(transmit_fifo.w_level),
self.adat_out .eq(nrzi_encoder.nrzi_out),
nrzi_encoder.data_in .eq(transmitted_frame.bit_select(transmit_counter, 1)),
self.underflow_out .eq(0)
]
#
# Fill the transmit FIFO in the sync domain
#
channel_counter = Signal(3)
# make sure, en is only asserted when explicitly strobed
comb += samples_write_port.en.eq(0)
write_frame_border = [
transmit_fifo.w_data .eq((1 << frame_border_flag) | self.user_data_in),
transmit_fifo.w_en .eq(1)
]
with m.FSM():
with m.State("DATA"):
with m.If(self.ready_out):
with m.If(self.valid_in):
comb += [
samples_write_port.data.eq(self.sample_in),
samples_write_port.addr.eq(self.addr_in),
samples_write_port.en.eq(1)
]
with m.If(self.last_in):
sync += channel_counter.eq(0)
comb += write_frame_border
m.next = "COMMIT"
# underflow: repeat last frame
with m.Elif(transmit_fifo.w_level == 0):
sync += channel_counter.eq(0)
comb += self.underflow_out.eq(1)
comb += write_frame_border
m.next = "COMMIT"
with m.State("COMMIT"):
with m.If(transmit_fifo.w_rdy):
comb += [
self.ready_out.eq(0),
samples_read_port.addr .eq(channel_counter),
transmit_fifo.w_data .eq(samples_read_port.data),
transmit_fifo.w_en .eq(1)
]
sync += channel_counter.eq(channel_counter + 1)
with m.If(channel_counter == 7):
m.next = "DATA"
#
# Read the FIFO and send data in the adat domain
#
# 4b/5b coding: Every 24 bit channel has 6 nibbles.
# 1 bit before the sync pad and one bit before the user data nibble
filler_bits = [Const(1, 1) for _ in range(7)]
adat += transmit_counter.eq(transmit_counter - 1)
comb += transmit_fifo.r_en.eq(0)
with m.If(transmit_counter == 0):
with m.If(transmit_fifo.r_rdy):
comb += transmit_fifo.r_en.eq(1)
with m.If(transmit_fifo.r_data[frame_border_flag] == 0):
adat += [
transmit_counter.eq(29),
# generate the adat data for one channel 0b1dddd1dddd1dddd1dddd1dddd1dddd where d is the PCM audio data
transmitted_frame.eq(Cat(zip(list(self.chunks(transmit_fifo.r_data[:25], 4)), filler_bits)))
]
with m.Else():
adat += [
transmit_counter.eq(15),
# generate the adat sync_pad along with the user_bits 0b100000000001uuuu where u is user_data
transmitted_frame.eq((1 << 15) | (1 << 4) | transmit_fifo.r_data[:5])
]
with m.Else():
# this should not happen: panic / stop transmitting.
adat += [
transmitted_frame.eq(0x00),
transmit_counter.eq(4)
]
return m
class IntegratedLogicAnalyzer(Elaboratable):
""" Super-simple integrated-logic-analyzer generator class for LUNA.
Attributes
----------
trigger: Signal(), input
A strobe that determines when we should start sampling.
sampling: Signal(), output
Indicates when sampling is in progress.
complete: Signal(), output
Indicates when sampling is complete and ready to be read.
captured_sample_number: Signal(), input
Selects which sample the ILA will output. Effectively the address for the ILA's
sample buffer.
captured_sample: Signal(), output
The sample corresponding to the relevant sample number.
Can be broken apart by using Cat(*signals).
Parameters
----------
signals: iterable of Signals
An iterable of signals that should be captured by the ILA.
sample_depth: int
The depth of the desired buffer, in samples.
domain: string
The clock domain in which the ILA should operate.
sample_rate: float
Cosmetic indication of the sample rate. Used to format output.
samples_pretrigger: int
The number of our samples which should be captured _before_ the trigger.
This also can act like an implicit synchronizer; so asynchronous inputs
are allowed if this number is >= 2. Note that the trigger strobe is read
on the rising edge of the clock.
"""
def __init__(self,
*,
signals,
sample_depth,
domain="sync",
sample_rate=60e6,
samples_pretrigger=1):
self.domain = domain
self.signals = signals
self.inputs = Cat(*signals)
self.sample_width = len(self.inputs)
self.sample_depth = sample_depth
self.samples_pretrigger = samples_pretrigger
self.sample_rate = sample_rate
self.sample_period = 1 / sample_rate
#
# Create a backing store for our samples.
#
self.mem = Memory(width=self.sample_width,
depth=sample_depth,
name="ila_buffer")
#
# I/O port
#
self.trigger = Signal()
self.sampling = Signal()
self.complete = Signal()
self.captured_sample_number = Signal(range(0, self.sample_depth))
self.captured_sample = Signal(self.sample_width)
def elaborate(self, platform):
m = Module()
# Memory ports.
write_port = self.mem.write_port()
read_port = self.mem.read_port(domain="sync")
m.submodules += [write_port, read_port]
# If necessary, create synchronized versions of the relevant signals.
if self.samples_pretrigger >= 2:
delayed_inputs = Signal.like(self.inputs)
m.submodules += FFSynchronizer(self.inputs,
delayed_inputs,
stages=self.samples_pretrigger)
elif self.samples_pretrigger == 1:
delayed_inputs = Signal.like(self.inputs)
m.d.sync += delayed_inputs.eq(self.inputs)
else:
delayed_inputs = self.inputs
# Counter that keeps track of our write position.
write_position = Signal(range(0, self.sample_depth))
# Set up our write port to capture the input signals,
# and our read port to provide the output.
m.d.comb += [
write_port.data.eq(delayed_inputs),
write_port.addr.eq(write_position),
self.captured_sample.eq(read_port.data),
read_port.addr.eq(self.captured_sample_number)
]
# Don't sample unless our FSM asserts our sample signal explicitly.
m.d.sync += write_port.en.eq(0)
with m.FSM(name="ila_state") as fsm:
m.d.comb += self.sampling.eq(~fsm.ongoing("IDLE"))
# IDLE: wait for the trigger strobe
with m.State('IDLE'):
with m.If(self.trigger):
m.next = 'SAMPLE'
# Grab a sample as our trigger is asserted.
m.d.sync += [
write_port.en.eq(1),
write_position.eq(0),
self.complete.eq(0),
]
# SAMPLE: do our sampling
with m.State('SAMPLE'):
# Sample until we run out of samples.
m.d.sync += [
write_port.en.eq(1),
write_position.eq(write_position + 1),
]
# If this is the last sample, we're done. Finish up.
with m.If(write_position + 1 == self.sample_depth):
m.next = "IDLE"
m.d.sync += [self.complete.eq(1), write_port.en.eq(0)]
# Convert our sync domain to the domain requested by the user, if necessary.
if self.domain != "sync":
m = DomainRenamer(self.domain)(m)
return m
def elaborate(self, platform):
m = Module()
# Range shortcuts for internal signals.
address_range = range(0, self.depth + 1)
#
# Core internal "backing store".
#
memory = Memory(width=self.width, depth=self.depth + 1, name=self.name)
m.submodules.read_port = read_port = memory.read_port()
m.submodules.write_port = write_port = memory.write_port()
# Always connect up our memory's data/en ports to ours.
m.d.comb += [
self.read_data.eq(read_port.data),
write_port.data.eq(self.write_data),
write_port.en.eq(self.write_en & ~self.full)
]
#
# Write port.
#
# We'll track two pieces of data: our _committed_ write position, and our current un-committed write one.
# This will allow us to rapidly backtrack to our pre-commit position.
committed_write_pointer = Signal(address_range)
current_write_pointer = Signal(address_range)
m.d.comb += write_port.addr.eq(current_write_pointer)
# Compute the location for the next write, accounting for wraparound. We'll not assume a binary-sized
# buffer; so we'll compute the wraparound manually.
next_write_pointer = Signal.like(current_write_pointer)
with m.If(current_write_pointer == self.depth):
m.d.comb += next_write_pointer.eq(0)
with m.Else():
m.d.comb += next_write_pointer.eq(current_write_pointer + 1)
# If we're writing to the fifo, update our current write position.
with m.If(self.write_en & ~self.full):
m.d.sync += current_write_pointer.eq(next_write_pointer)
# If we're committing a FIFO write, update our committed position.
with m.If(self.write_commit):
m.d.sync += committed_write_pointer.eq(current_write_pointer)
# If we're discarding our current write, reset our current position,
with m.If(self.write_discard):
m.d.sync += current_write_pointer.eq(committed_write_pointer)
#
# Read port.
#
# We'll track two pieces of data: our _committed_ read position, and our current un-committed read one.
# This will allow us to rapidly backtrack to our pre-commit position.
committed_read_pointer = Signal(address_range)
current_read_pointer = Signal(address_range)
# Compute the location for the next read, accounting for wraparound. We'll not assume a binary-sized
# buffer; so we'll compute the wraparound manually.
next_read_pointer = Signal.like(current_read_pointer)
with m.If(current_read_pointer == self.depth):
m.d.comb += next_read_pointer.eq(0)
with m.Else():
m.d.comb += next_read_pointer.eq(current_read_pointer + 1)
# Our memory always takes a single cycle to provide its read output; so we'll update its address
# "one cycle in advance". Accordingly, if we're about to advance the FIFO, we'll use the next read
# address as our input. If we're not, we'll use the current one.
with m.If(self.read_en & ~self.empty):
m.d.comb += read_port.addr.eq(next_read_pointer)
with m.Else():
m.d.comb += read_port.addr.eq(current_read_pointer)
# If we're reading from our the fifo, update our current read position.
with m.If(self.read_en & ~self.empty):
m.d.sync += current_read_pointer.eq(next_read_pointer)
# If we're committing a FIFO write, update our committed position.
with m.If(self.read_commit):
m.d.sync += committed_read_pointer.eq(current_read_pointer)
# If we're discarding our current write, reset our current position,
with m.If(self.read_discard):
m.d.sync += current_read_pointer.eq(committed_read_pointer)
#
# FIFO status.
#
# Our FIFO is empty if our read and write pointers are in the same. We'll use the current
# read position (which leads ahead) and the committed write position (which lags behind).
m.d.comb += self.empty.eq(
current_read_pointer == committed_write_pointer)
# For our space available, we'll use the current write position (which leads ahead) and our committed
# read position (which lags behind). This yields two cases: one where the buffer isn't wrapped around,
# and one where it is.
with m.If(self.full):
m.d.comb += self.space_available.eq(0)
with m.Elif(committed_read_pointer <= current_write_pointer):
m.d.comb += self.space_available.eq(self.depth -
(current_write_pointer -
committed_read_pointer))
with m.Else():
m.d.comb += self.space_available.eq(committed_read_pointer -
current_write_pointer - 1)
# Our FIFO is full if we don't have any space available.
m.d.comb += self.full.eq(next_write_pointer == committed_read_pointer)
# If we're not supposed to be in the sync domain, rename our sync domain to the target.
if self.domain != "sync":
m = DomainRenamer({"sync": self.domain})(m)
return m