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mirror of https://github.com/m-labs/artiq.git synced 2024-12-24 10:54:02 +08:00

Merge branch 'sed-merge'

This commit is contained in:
Sebastien Bourdeauducq 2018-01-10 13:14:39 +08:00
commit 6d58c4390b
48 changed files with 2122 additions and 1243 deletions

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@ -1,9 +1,9 @@
from artiq.coredevice import exceptions, dds, spi
from artiq.coredevice.exceptions import (RTIOUnderflow, RTIOSequenceError, RTIOOverflow)
from artiq.coredevice.exceptions import (RTIOUnderflow, RTIOOverflow)
from artiq.coredevice.dds import (PHASE_MODE_CONTINUOUS, PHASE_MODE_ABSOLUTE,
PHASE_MODE_TRACKING)
__all__ = []
__all__ += ["RTIOUnderflow", "RTIOSequenceError", "RTIOOverflow"]
__all__ += ["RTIOUnderflow", "RTIOOverflow"]
__all__ += ["PHASE_MODE_CONTINUOUS", "PHASE_MODE_ABSOLUTE",
"PHASE_MODE_TRACKING"]

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@ -27,9 +27,9 @@ class ExceptionType(Enum):
legacy_o_sequence_error_reset = 0b010001
legacy_o_collision_reset = 0b010010
legacy_i_overflow_reset = 0b100000
legacy_o_sequence_error = 0b010101
o_underflow = 0b010100
o_sequence_error = 0b010101
i_overflow = 0b100001

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@ -78,13 +78,6 @@ class RTIOUnderflow(Exception):
"""
artiq_builtin = True
class RTIOSequenceError(Exception):
"""Raised when an event is submitted on a given channel with a timestamp
not larger than the previous one.
The offending event is discarded and the RTIO core keeps operating.
"""
artiq_builtin = True
class RTIOOverflow(Exception):
"""Raised when at least one event could not be registered into the RTIO
@ -96,26 +89,32 @@ class RTIOOverflow(Exception):
"""
artiq_builtin = True
class DMAError(Exception):
"""Raised when performing an invalid DMA operation."""
artiq_builtin = True
class DDSError(Exception):
"""Raised when attempting to start a DDS batch while already in a batch,
when too many commands are batched, and when DDS channel settings are
incorrect.
"""
class WatchdogExpired(Exception):
"""Raised when a watchdog expires."""
class ClockFailure(Exception):
"""Raised when RTIO PLL has lost lock."""
class I2CError(Exception):
"""Raised when a I2C transaction fails."""
pass
class SPIError(Exception):
"""Raised when a SPI transaction fails."""
pass

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@ -21,6 +21,7 @@ class DMABlink(EnvExperiment):
def run(self):
self.core.reset()
self.record()
handle = self.core_dma.get_handle("blink")
self.core.break_realtime()
for i in range(5):
self.core_dma.playback("blink")
self.core_dma.playback_handle(handle)

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@ -108,11 +108,8 @@ static mut API: &'static [(&'static str, *const ())] = &[
api!(dma_retrieve = ::dma_retrieve),
api!(dma_playback = ::dma_playback),
api!(drtio_get_channel_state = ::rtio::drtio_dbg::get_channel_state),
api!(drtio_reset_channel_state = ::rtio::drtio_dbg::reset_channel_state),
api!(drtio_get_fifo_space = ::rtio::drtio_dbg::get_fifo_space),
api!(drtio_get_packet_counts = ::rtio::drtio_dbg::get_packet_counts),
api!(drtio_get_fifo_space_req_count = ::rtio::drtio_dbg::get_fifo_space_req_count),
api!(drtio_get_buffer_space_req_count = ::rtio::drtio_dbg::get_buffer_space_req_count),
api!(i2c_start = ::nrt_bus::i2c::start),
api!(i2c_restart = ::nrt_bus::i2c::restart),

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@ -384,22 +384,13 @@ extern fn dma_playback(timestamp: i64, ptr: i32) {
while csr::rtio_dma::enable_read() != 0 {}
csr::cri_con::selected_write(0);
let status = csr::rtio_dma::error_status_read();
if status != 0 {
if csr::rtio_dma::underflow_read() != 0 {
let timestamp = csr::rtio_dma::error_timestamp_read();
let channel = csr::rtio_dma::error_channel_read();
if status & rtio::RTIO_O_STATUS_UNDERFLOW != 0 {
csr::rtio_dma::error_underflow_reset_write(1);
raise!("RTIOUnderflow",
"RTIO underflow at {0} mu, channel {1}",
timestamp as i64, channel as i64, 0)
}
if status & rtio::RTIO_O_STATUS_SEQUENCE_ERROR != 0 {
csr::rtio_dma::error_sequence_error_reset_write(1);
raise!("RTIOSequenceError",
"RTIO sequence error at {0} mu, channel {1}",
timestamp as i64, channel as i64, 0)
}
csr::rtio_dma::underflow_write(1);
raise!("RTIOUnderflow",
"RTIO underflow at {0} mu, channel {1}",
timestamp as i64, channel as i64, 0)
}
}
}

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@ -1,4 +1,3 @@
#[cfg(has_rtio)]
mod imp {
use core::ptr::{read_volatile, write_volatile};
@ -10,7 +9,6 @@ mod imp {
pub const RTIO_O_STATUS_WAIT: u8 = 1;
pub const RTIO_O_STATUS_UNDERFLOW: u8 = 2;
pub const RTIO_O_STATUS_SEQUENCE_ERROR: u8 = 4;
pub const RTIO_I_STATUS_WAIT_EVENT: u8 = 1;
pub const RTIO_I_STATUS_OVERFLOW: u8 = 2;
pub const RTIO_I_STATUS_WAIT_STATUS: u8 = 4;
@ -49,11 +47,6 @@ mod imp {
"RTIO underflow at {0} mu, channel {1}, slack {2} mu",
timestamp, channel as i64, timestamp - get_counter())
}
if status & RTIO_O_STATUS_SEQUENCE_ERROR != 0 {
raise!("RTIOSequenceError",
"RTIO sequence error at {0} mu, channel {1}",
timestamp, channel as i64, 0)
}
}
pub extern fn output(timestamp: i64, channel: i32, addr: i32, data: i32) {
@ -204,23 +197,6 @@ pub mod drtio_dbg {
use ::recv;
use kernel_proto::*;
#[repr(C)]
pub struct ChannelState(i32, i64);
pub extern fn get_channel_state(channel: i32) -> ChannelState {
send(&DrtioChannelStateRequest { channel: channel as u32 });
recv!(&DrtioChannelStateReply { fifo_space, last_timestamp }
=> ChannelState(fifo_space as i32, last_timestamp as i64))
}
pub extern fn reset_channel_state(channel: i32) {
send(&DrtioResetChannelStateRequest { channel: channel as u32 })
}
pub extern fn get_fifo_space(channel: i32) {
send(&DrtioGetFifoSpaceRequest { channel: channel as u32 })
}
#[repr(C)]
pub struct PacketCounts(i32, i32);
@ -230,9 +206,9 @@ pub mod drtio_dbg {
=> PacketCounts(tx_cnt as i32, rx_cnt as i32))
}
pub extern fn get_fifo_space_req_count(linkno: i32) -> i32 {
send(&DrtioFifoSpaceReqCountRequest { linkno: linkno as u8 });
recv!(&DrtioFifoSpaceReqCountReply { cnt }
pub extern fn get_buffer_space_req_count(linkno: i32) -> i32 {
send(&DrtioBufferSpaceReqCountRequest { linkno: linkno as u8 });
recv!(&DrtioBufferSpaceReqCountReply { cnt }
=> cnt as i32)
}
}

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@ -20,8 +20,9 @@ pub enum Packet {
RtioErrorRequest,
RtioNoErrorReply,
RtioErrorCollisionReply,
RtioErrorBusyReply,
RtioErrorSequenceErrorReply { channel: u16 },
RtioErrorCollisionReply { channel: u16 },
RtioErrorBusyReply { channel: u16 },
MonitorRequest { channel: u16, probe: u8 },
MonitorReply { value: u32 },
@ -54,8 +55,15 @@ impl Packet {
0x20 => Packet::RtioErrorRequest,
0x21 => Packet::RtioNoErrorReply,
0x22 => Packet::RtioErrorCollisionReply,
0x23 => Packet::RtioErrorBusyReply,
0x22 => Packet::RtioErrorSequenceErrorReply {
channel: read_u16(reader)?
},
0x23 => Packet::RtioErrorCollisionReply {
channel: read_u16(reader)?
},
0x24 => Packet::RtioErrorBusyReply {
channel: read_u16(reader)?
},
0x40 => Packet::MonitorRequest {
channel: read_u16(reader)?,
@ -144,8 +152,18 @@ impl Packet {
Packet::RtioErrorRequest => write_u8(writer, 0x20)?,
Packet::RtioNoErrorReply => write_u8(writer, 0x21)?,
Packet::RtioErrorCollisionReply => write_u8(writer, 0x22)?,
Packet::RtioErrorBusyReply => write_u8(writer, 0x23)?,
Packet::RtioErrorSequenceErrorReply { channel } => {
write_u8(writer, 0x22)?;
write_u16(writer, channel)?;
},
Packet::RtioErrorCollisionReply { channel } => {
write_u8(writer, 0x23)?;
write_u16(writer, channel)?;
},
Packet::RtioErrorBusyReply { channel } => {
write_u8(writer, 0x24)?;
write_u16(writer, channel)?;
},
Packet::MonitorRequest { channel, probe } => {
write_u8(writer, 0x40)?;

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@ -46,14 +46,10 @@ pub enum Message<'a> {
duration: u64
},
DrtioChannelStateRequest { channel: u32 },
DrtioChannelStateReply { fifo_space: u16, last_timestamp: u64 },
DrtioResetChannelStateRequest { channel: u32 },
DrtioGetFifoSpaceRequest { channel: u32 },
DrtioPacketCountRequest { linkno: u8 },
DrtioPacketCountReply { tx_cnt: u32, rx_cnt: u32 },
DrtioFifoSpaceReqCountRequest { linkno: u8 },
DrtioFifoSpaceReqCountReply { cnt: u32 },
DrtioBufferSpaceReqCountRequest { linkno: u8 },
DrtioBufferSpaceReqCountReply { cnt: u32 },
RunFinished,
RunException {

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@ -327,31 +327,16 @@ pub fn process_kern_hwreq(io: &Io, request: &kern::Message) -> io::Result<bool>
kern_acknowledge()
}
#[cfg(has_rtio_core)]
&kern::DrtioChannelStateRequest { channel } => {
let (fifo_space, last_timestamp) = rtio_mgt::drtio_dbg::get_channel_state(channel);
kern_send(io, &kern::DrtioChannelStateReply { fifo_space: fifo_space,
last_timestamp: last_timestamp })
}
#[cfg(has_rtio_core)]
&kern::DrtioResetChannelStateRequest { channel } => {
rtio_mgt::drtio_dbg::reset_channel_state(channel);
kern_acknowledge()
}
#[cfg(has_rtio_core)]
&kern::DrtioGetFifoSpaceRequest { channel } => {
rtio_mgt::drtio_dbg::get_fifo_space(channel);
kern_acknowledge()
}
#[cfg(has_rtio_core)]
&kern::DrtioPacketCountRequest { linkno } => {
let (tx_cnt, rx_cnt) = rtio_mgt::drtio_dbg::get_packet_counts(linkno);
kern_send(io, &kern::DrtioPacketCountReply { tx_cnt: tx_cnt, rx_cnt: rx_cnt })
}
#[cfg(has_rtio_core)]
&kern::DrtioFifoSpaceReqCountRequest { linkno } => {
let cnt = rtio_mgt::drtio_dbg::get_fifo_space_req_count(linkno);
kern_send(io, &kern::DrtioFifoSpaceReqCountReply { cnt: cnt })
&kern::DrtioBufferSpaceReqCountRequest { linkno } => {
let cnt = rtio_mgt::drtio_dbg::get_buffer_space_req_count(linkno);
kern_send(io, &kern::DrtioBufferSpaceReqCountReply { cnt: cnt })
}
&kern::I2cStartRequest { busno } => {

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@ -72,21 +72,11 @@ pub mod drtio {
unsafe {
(csr::DRTIO[linkidx].reset_write)(1);
while (csr::DRTIO[linkidx].o_wait_read)() == 1 {}
}
// TODO: determine actual number of remote FIFOs
for channel in 0..16 {
unsafe {
(csr::DRTIO[linkidx].chan_sel_override_write)(channel);
(csr::DRTIO[linkidx].chan_sel_override_en_write)(1);
(csr::DRTIO[linkidx].o_reset_channel_status_write)(1);
(csr::DRTIO[linkidx].o_get_fifo_space_write)(1);
while (csr::DRTIO[linkidx].o_wait_read)() == 1 {}
info!("[LINK#{}] FIFO space on channel {} is {}",
linkno, channel, (csr::DRTIO[linkidx].o_dbg_fifo_space_read)());
(csr::DRTIO[linkidx].chan_sel_override_en_write)(0);
}
(csr::DRTIO[linkidx].o_get_buffer_space_write)(1);
while (csr::DRTIO[linkidx].o_wait_read)() == 1 {}
info!("[LINK#{}] buffer space is {}",
linkno, (csr::DRTIO[linkidx].o_dbg_buffer_space_read)());
}
}
@ -129,7 +119,7 @@ pub mod drtio {
error!("[LINK#{}] received truncated packet", linkno);
}
if errors & 4 != 0 {
error!("[LINK#{}] timeout attempting to get remote FIFO space", linkno);
error!("[LINK#{}] timeout attempting to get remote buffer space", linkno);
}
}
}
@ -138,10 +128,12 @@ pub mod drtio {
drtioaux::hw::send_link(linkno, &drtioaux::Packet::RtioErrorRequest).unwrap();
match drtioaux::hw::recv_timeout_link(linkno, None) {
Ok(drtioaux::Packet::RtioNoErrorReply) => (),
Ok(drtioaux::Packet::RtioErrorCollisionReply) =>
error!("[LINK#{}] RTIO collision", linkno),
Ok(drtioaux::Packet::RtioErrorBusyReply) =>
error!("[LINK#{}] RTIO busy", linkno),
Ok(drtioaux::Packet::RtioErrorSequenceErrorReply { channel }) =>
error!("[LINK#{}] RTIO sequence error involving channel {}", linkno, channel),
Ok(drtioaux::Packet::RtioErrorCollisionReply { channel }) =>
error!("[LINK#{}] RTIO collision involving channel {}", linkno, channel),
Ok(drtioaux::Packet::RtioErrorBusyReply { channel }) =>
error!("[LINK#{}] RTIO busy error involving channel {}", linkno, channel),
Ok(_) => error!("[LINK#{}] received unexpected aux packet", linkno),
Err(e) => error!("[LINK#{}] aux packet error ({})", linkno, e)
}
@ -197,10 +189,16 @@ fn async_error_thread(io: Io) {
io.until(|| csr::rtio_core::async_error_read() != 0).unwrap();
let errors = csr::rtio_core::async_error_read();
if errors & 1 != 0 {
error!("RTIO collision");
error!("RTIO collision involving channel {}",
csr::rtio_core::collision_channel_read());
}
if errors & 2 != 0 {
error!("RTIO busy");
error!("RTIO busy error involving channel {}",
csr::rtio_core::busy_channel_read());
}
if errors & 4 != 0 {
error!("RTIO sequence error involving channel {}",
csr::rtio_core::sequence_error_channel_read());
}
csr::rtio_core::async_error_write(errors);
}
@ -260,42 +258,6 @@ pub fn init_core() {
pub mod drtio_dbg {
use board::csr;
// TODO: routing
pub fn get_channel_state(channel: u32) -> (u16, u64) {
let linkno = ((channel >> 16) - 1) as usize;
let node_channel = channel as u16;
unsafe {
(csr::DRTIO[linkno].chan_sel_override_write)(node_channel as u16);
(csr::DRTIO[linkno].chan_sel_override_en_write)(1);
let fifo_space = (csr::DRTIO[linkno].o_dbg_fifo_space_read)();
let last_timestamp = (csr::DRTIO[linkno].o_dbg_last_timestamp_read)();
(csr::DRTIO[linkno].chan_sel_override_en_write)(0);
(fifo_space, last_timestamp)
}
}
pub fn reset_channel_state(channel: u32) {
let linkno = ((channel >> 16) - 1) as usize;
let node_channel = channel as u16;
unsafe {
(csr::DRTIO[linkno].chan_sel_override_write)(node_channel);
(csr::DRTIO[linkno].chan_sel_override_en_write)(1);
(csr::DRTIO[linkno].o_reset_channel_status_write)(1);
(csr::DRTIO[linkno].chan_sel_override_en_write)(0);
}
}
pub fn get_fifo_space(channel: u32) {
let linkno = ((channel >> 16) - 1) as usize;
let node_channel = channel as u16;
unsafe {
(csr::DRTIO[linkno].chan_sel_override_write)(node_channel);
(csr::DRTIO[linkno].chan_sel_override_en_write)(1);
(csr::DRTIO[linkno].o_get_fifo_space_write)(1);
(csr::DRTIO[linkno].chan_sel_override_en_write)(0);
}
}
pub fn get_packet_counts(linkno: u8) -> (u32, u32) {
let linkno = linkno as usize;
unsafe {
@ -305,23 +267,17 @@ pub mod drtio_dbg {
}
}
pub fn get_fifo_space_req_count(linkno: u8) -> u32 {
pub fn get_buffer_space_req_count(linkno: u8) -> u32 {
let linkno = linkno as usize;
unsafe {
(csr::DRTIO[linkno].o_dbg_fifo_space_req_cnt_read)()
(csr::DRTIO[linkno].o_dbg_buffer_space_req_cnt_read)()
}
}
}
#[cfg(not(has_drtio))]
pub mod drtio_dbg {
pub fn get_channel_state(_channel: u32) -> (u16, u64) { (0, 0) }
pub fn reset_channel_state(_channel: u32) {}
pub fn get_fifo_space(_channel: u32) {}
pub fn get_packet_counts(_linkno: u8) -> (u32, u32) { (0, 0) }
pub fn get_fifo_space_req_count(_linkno: u8) -> u32 { 0 }
pub fn get_buffer_space_req_count(_linkno: u8) -> u32 { 0 }
}

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@ -30,16 +30,28 @@ fn process_aux_packet(p: &drtioaux::Packet) {
errors = (csr::DRTIO[0].rtio_error_read)();
}
if errors & 1 != 0 {
let channel;
unsafe {
channel = (csr::DRTIO[0].sequence_error_channel_read)();
(csr::DRTIO[0].rtio_error_write)(1);
}
drtioaux::hw::send_link(0, &drtioaux::Packet::RtioErrorCollisionReply).unwrap();
drtioaux::hw::send_link(0, &drtioaux::Packet::RtioErrorSequenceErrorReply { channel: channel }).unwrap();
} else if errors & 2 != 0 {
let channel;
unsafe {
channel = (csr::DRTIO[0].collision_channel_read)();
(csr::DRTIO[0].rtio_error_write)(2);
}
drtioaux::hw::send_link(0, &drtioaux::Packet::RtioErrorBusyReply).unwrap();
} else {
drtioaux::hw::send_link(0, &drtioaux::Packet::RtioErrorCollisionReply { channel: channel }).unwrap();
} else if errors & 4 != 0 {
let channel;
unsafe {
channel = (board::csr::DRTIO[0].busy_channel_read)();
(board::csr::DRTIO[0].rtio_error_write)(4);
}
drtioaux::hw::send_link(0, &drtioaux::Packet::RtioErrorBusyReply { channel: channel }).unwrap();
}
else {
drtioaux::hw::send_link(0, &drtioaux::Packet::RtioNoErrorReply).unwrap();
}
}
@ -160,9 +172,6 @@ fn process_errors() {
if errors & 8 != 0 {
error!("write overflow");
}
if errors & 16 != 0 {
error!("write sequence error");
}
}

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@ -3,10 +3,11 @@ from types import SimpleNamespace
from migen import *
from migen.genlib.cdc import ElasticBuffer
from artiq.gateware.rtio.sed.core import *
from artiq.gateware.rtio.input_collector import *
from artiq.gateware.drtio import (link_layer, aux_controller,
rt_packet_satellite, rt_ios_satellite,
rt_errors_satellite,
rt_packet_master, rt_controller_master)
rt_packet_satellite, rt_errors_satellite,
rt_packet_master, rt_controller_master)
class ChannelInterface:
@ -49,7 +50,8 @@ class GenericRXSynchronizer(Module):
class DRTIOSatellite(Module):
def __init__(self, chanif, channels, rx_synchronizer=None, fine_ts_width=3, full_ts_width=63):
def __init__(self, chanif, channels, rx_synchronizer=None, fine_ts_width=3,
lane_count=8, fifo_depth=128):
if rx_synchronizer is None:
rx_synchronizer = GenericRXSynchronizer()
self.submodules += rx_synchronizer
@ -77,11 +79,30 @@ class DRTIOSatellite(Module):
self.submodules.rt_packet = ClockDomainsRenamer("rtio")(
rt_packet_satellite.RTPacketSatellite(link_layer_sync))
self.submodules.ios = rt_ios_satellite.IOS(
self.rt_packet, channels, fine_ts_width, full_ts_width)
coarse_ts = Signal(64 - fine_ts_width)
self.sync.rtio += \
If(self.rt_packet.tsc_load,
coarse_ts.eq(self.rt_packet.tsc_load_value)
).Else(
coarse_ts.eq(coarse_ts + 1)
)
self.comb += self.rt_packet.cri.counter.eq(coarse_ts << fine_ts_width)
self.submodules.outputs = ClockDomainsRenamer("rio")(
SED(channels, fine_ts_width, "sync",
lane_count=lane_count, fifo_depth=fifo_depth,
enable_spread=False, report_buffer_space=True,
interface=self.rt_packet.cri))
self.comb += self.outputs.coarse_timestamp.eq(coarse_ts)
self.sync += self.outputs.minimum_coarse_timestamp.eq(coarse_ts + 16)
self.submodules.inputs = ClockDomainsRenamer("rio")(
InputCollector(channels, fine_ts_width, "sync",
interface=self.rt_packet.cri))
self.comb += self.inputs.coarse_timestamp.eq(coarse_ts)
self.submodules.rt_errors = rt_errors_satellite.RTErrorsSatellite(
self.rt_packet, self.ios)
self.rt_packet, self.outputs)
self.clock_domains.cd_rio = ClockDomain()
self.clock_domains.cd_rio_phy = ClockDomain()

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@ -7,7 +7,7 @@ from migen.genlib.resetsync import AsyncResetSynchronizer
from misoc.interconnect.csr import *
from artiq.gateware.rtio.cdc import RTIOCounter
from artiq.gateware.rtio.cdc import GrayCodeTransfer
from artiq.gateware.rtio import cri
@ -15,9 +15,6 @@ class _CSRs(AutoCSR):
def __init__(self):
self.protocol_error = CSR(3)
self.chan_sel_override = CSRStorage(16)
self.chan_sel_override_en = CSRStorage()
self.tsc_correction = CSRStorage(64)
self.set_time = CSR()
self.underflow_margin = CSRStorage(16, reset=200)
@ -25,14 +22,30 @@ class _CSRs(AutoCSR):
self.reset = CSR()
self.reset_phy = CSR()
self.o_get_fifo_space = CSR()
self.o_dbg_fifo_space = CSRStatus(16)
self.o_dbg_last_timestamp = CSRStatus(64)
self.o_dbg_fifo_space_req_cnt = CSRStatus(32)
self.o_reset_channel_status = CSR()
self.o_get_buffer_space = CSR()
self.o_dbg_buffer_space = CSRStatus(16)
self.o_dbg_buffer_space_req_cnt = CSRStatus(32)
self.o_wait = CSRStatus()
class RTIOCounter(Module):
def __init__(self, width):
self.width = width
# Timestamp counter in RTIO domain
self.value_rtio = Signal(width)
# Timestamp counter resynchronized to sys domain
# Lags behind value_rtio, monotonic and glitch-free
self.value_sys = Signal(width)
# # #
# note: counter is in rtio domain and never affected by the reset CSRs
self.sync.rtio += self.value_rtio.eq(self.value_rtio + 1)
gt = GrayCodeTransfer(width)
self.submodules += gt
self.comb += gt.i.eq(self.value_rtio), self.value_sys.eq(gt.o)
class RTController(Module):
def __init__(self, rt_packet, channel_count, fine_ts_width):
self.csrs = _CSRs()
@ -41,27 +54,20 @@ class RTController(Module):
# protocol errors
err_unknown_packet_type = Signal()
err_packet_truncated = Signal()
signal_fifo_space_timeout = Signal()
err_fifo_space_timeout = Signal()
signal_buffer_space_timeout = Signal()
err_buffer_space_timeout = Signal()
self.sync.sys_with_rst += [
If(self.csrs.protocol_error.re,
If(self.csrs.protocol_error.r[0], err_unknown_packet_type.eq(0)),
If(self.csrs.protocol_error.r[1], err_packet_truncated.eq(0)),
If(self.csrs.protocol_error.r[2], err_fifo_space_timeout.eq(0))
If(self.csrs.protocol_error.r[2], err_buffer_space_timeout.eq(0))
),
If(rt_packet.err_unknown_packet_type, err_unknown_packet_type.eq(1)),
If(rt_packet.err_packet_truncated, err_packet_truncated.eq(1)),
If(signal_fifo_space_timeout, err_fifo_space_timeout.eq(1))
If(signal_buffer_space_timeout, err_buffer_space_timeout.eq(1))
]
self.comb += self.csrs.protocol_error.w.eq(
Cat(err_unknown_packet_type, err_packet_truncated, err_fifo_space_timeout))
# channel selection
chan_sel = Signal(16)
self.comb += chan_sel.eq(
Mux(self.csrs.chan_sel_override_en.storage,
self.csrs.chan_sel_override.storage,
self.cri.chan_sel[:16]))
Cat(err_unknown_packet_type, err_packet_truncated, err_buffer_space_timeout))
# master RTIO counter and counter synchronization
self.submodules.counter = RTIOCounter(64-fine_ts_width)
@ -104,26 +110,16 @@ class RTController(Module):
self.comb += self.cd_rtio_with_rst.clk.eq(ClockSignal("rtio"))
self.specials += AsyncResetSynchronizer(self.cd_rtio_with_rst, local_reset)
# remote channel status cache
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
# common packet fields
rt_packet_fifo_request = Signal()
chan_sel = self.cri.chan_sel[:16]
rt_packet_buffer_request = Signal()
rt_packet_read_request = Signal()
self.comb += [
fifo_spaces.adr.eq(chan_sel),
last_timestamps.adr.eq(chan_sel),
last_timestamps.dat_w.eq(self.cri.timestamp),
rt_packet.sr_channel.eq(chan_sel),
rt_packet.sr_address.eq(self.cri.o_address),
rt_packet.sr_data.eq(self.cri.o_data),
rt_packet.sr_timestamp.eq(self.cri.timestamp),
If(rt_packet_fifo_request,
If(rt_packet_buffer_request,
rt_packet.sr_notwrite.eq(1),
rt_packet.sr_address.eq(0)
),
@ -136,30 +132,28 @@ class RTController(Module):
# output status
o_status_wait = Signal()
o_status_underflow = Signal()
o_status_sequence_error = Signal()
self.comb += [
self.cri.o_status.eq(Cat(
o_status_wait, o_status_underflow, o_status_sequence_error)),
o_status_wait, o_status_underflow)),
self.csrs.o_wait.status.eq(o_status_wait)
]
o_sequence_error_set = Signal()
o_underflow_set = Signal()
self.sync.sys_with_rst += [
If(self.cri.cmd == cri.commands["write"],
o_status_underflow.eq(0),
o_status_sequence_error.eq(0),
o_status_underflow.eq(0)
),
If(o_underflow_set, o_status_underflow.eq(1)),
If(o_sequence_error_set, o_status_sequence_error.eq(1))
If(o_underflow_set, o_status_underflow.eq(1))
]
timeout_counter = WaitTimer(8191)
self.submodules += timeout_counter
cond_sequence_error = self.cri.timestamp < last_timestamps.dat_r
cond_underflow = ((self.cri.timestamp[fine_ts_width:]
cond_underflow = Signal()
self.comb += cond_underflow.eq((self.cri.timestamp[fine_ts_width:]
- self.csrs.underflow_margin.storage[fine_ts_width:]) < self.counter.value_sys)
buffer_space = Signal(16)
# input status
i_status_wait_event = Signal()
i_status_overflow = Signal()
@ -190,56 +184,51 @@ class RTController(Module):
fsm.act("IDLE",
If(self.cri.cmd == cri.commands["write"],
If(cond_sequence_error,
o_sequence_error_set.eq(1)
).Elif(cond_underflow,
If(cond_underflow,
o_underflow_set.eq(1)
).Else(
NextState("WRITE")
)
),
If(self.cri.cmd == cri.commands["read"], NextState("READ")),
If(self.csrs.o_get_fifo_space.re, NextState("GET_FIFO_SPACE"))
If(self.csrs.o_get_buffer_space.re, NextState("GET_BUFFER_SPACE"))
)
fsm.act("WRITE",
o_status_wait.eq(1),
rt_packet.sr_stb.eq(1),
If(rt_packet.sr_ack,
fifo_spaces.we.eq(1),
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")
NextValue(buffer_space, buffer_space - 1),
If(buffer_space <= 1,
NextState("GET_BUFFER_SPACE")
).Else(
NextState("IDLE")
)
)
)
fsm.act("GET_FIFO_SPACE",
fsm.act("GET_BUFFER_SPACE",
o_status_wait.eq(1),
rt_packet.fifo_space_not_ack.eq(1),
rt_packet_fifo_request.eq(1),
rt_packet.buffer_space_not_ack.eq(1),
rt_packet_buffer_request.eq(1),
rt_packet.sr_stb.eq(1),
If(rt_packet.sr_ack,
NextState("GET_FIFO_SPACE_REPLY")
NextState("GET_BUFFER_SPACE_REPLY")
)
)
fsm.act("GET_FIFO_SPACE_REPLY",
fsm.act("GET_BUFFER_SPACE_REPLY",
o_status_wait.eq(1),
fifo_spaces.dat_w.eq(rt_packet.fifo_space),
fifo_spaces.we.eq(1),
rt_packet.fifo_space_not_ack.eq(1),
If(rt_packet.fifo_space_not,
If(rt_packet.fifo_space != 0,
NextValue(buffer_space, rt_packet.buffer_space),
rt_packet.buffer_space_not_ack.eq(1),
If(rt_packet.buffer_space_not,
If(rt_packet.buffer_space != 0,
NextState("IDLE")
).Else(
NextState("GET_FIFO_SPACE")
NextState("GET_BUFFER_SPACE")
)
),
timeout_counter.wait.eq(1),
If(timeout_counter.done,
signal_fifo_space_timeout.eq(1),
NextState("GET_FIFO_SPACE")
signal_buffer_space_timeout.eq(1),
NextState("GET_BUFFER_SPACE")
)
)
fsm.act("READ",
@ -260,21 +249,12 @@ class RTController(Module):
)
)
# channel state access
self.comb += [
self.csrs.o_dbg_fifo_space.status.eq(fifo_spaces.dat_r),
self.csrs.o_dbg_last_timestamp.status.eq(last_timestamps.dat_r),
If(self.csrs.o_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)
)
]
# debug CSRs
self.comb += self.csrs.o_dbg_buffer_space.status.eq(buffer_space),
self.sync += \
If((rt_packet.sr_stb & rt_packet.sr_ack & rt_packet_fifo_request),
self.csrs.o_dbg_fifo_space_req_cnt.status.eq(
self.csrs.o_dbg_fifo_space_req_cnt.status + 1)
If((rt_packet.sr_stb & rt_packet.sr_ack & rt_packet_buffer_request),
self.csrs.o_dbg_buffer_space_req_cnt.status.eq(
self.csrs.o_dbg_buffer_space_req_cnt.status + 1)
)
def get_csrs(self):

View File

@ -7,31 +7,63 @@ from artiq.gateware.rtio.cdc import BlindTransfer
class RTErrorsSatellite(Module, AutoCSR):
def __init__(self, rt_packet, ios):
self.protocol_error = CSR(5)
self.rtio_error = CSR(2)
def __init__(self, rt_packet, outputs):
self.protocol_error = CSR(4)
self.rtio_error = CSR(3)
self.sequence_error_channel = CSRStatus(16)
self.collision_channel = CSRStatus(16)
self.busy_channel = CSRStatus(16)
def error_csr(csr, *sources):
for n, source in enumerate(sources):
pending = Signal(related=source)
xfer = BlindTransfer(odomain="sys")
for n, (source, detect_edges, din, dout) in enumerate(sources):
assert isinstance(source, Signal)
if din is not None:
data_width = len(din)
else:
data_width = 0
xfer = BlindTransfer(odomain="sys", data_width=data_width)
self.submodules += xfer
self.comb += xfer.i.eq(source)
if detect_edges:
source_r = Signal()
self.sync.rio += source_r.eq(source)
self.comb += xfer.i.eq(source & source_r)
else:
self.comb += xfer.i.eq(source)
pending = Signal(related=source)
self.sync += [
If(csr.re & csr.r[n], pending.eq(0)),
If(xfer.o, pending.eq(1))
]
self.comb += csr.w[n].eq(pending)
# The master is normally responsible for avoiding output overflows,
# output underflows, and sequence errors.
# Error reports here are only for diagnosing internal ARTIQ bugs.
error_csr(self.protocol_error,
rt_packet.unknown_packet_type,
rt_packet.packet_truncated,
ios.write_underflow,
ios.write_overflow,
ios.write_sequence_error)
if din is not None:
self.comb += xfer.data_i.eq(din)
self.sync += If(xfer.o & ~pending, dout.eq(xfer.data_o))
# The master is normally responsible for avoiding output overflows
# and output underflows. The error reports here are only for diagnosing
# internal ARTIQ bugs.
underflow = Signal()
overflow = Signal()
self.comb += [
underflow.eq(outputs.cri.o_status[1]),
overflow.eq(outputs.cri.o_status[0])
]
error_csr(self.protocol_error,
(rt_packet.unknown_packet_type, False, None, None),
(rt_packet.packet_truncated, False, None, None),
(underflow, True, None, None),
(overflow, True, None, None)
)
error_csr(self.rtio_error,
ios.collision,
ios.busy)
(outputs.sequence_error, False,
outputs.sequence_error_channel, self.sequence_error_channel.status),
(outputs.collision, False,
outputs.collision_channel, self.collision_channel.status),
(outputs.busy, False,
outputs.busy_channel, self.busy_channel.status)
)

View File

@ -1,246 +0,0 @@
"""Real-time I/O scheduler for satellites"""
from migen import *
from migen.genlib.fifo import SyncFIFOBuffered
from migen.genlib.record import *
from artiq.gateware.rtio import rtlink
class IOS(Module):
def __init__(self, rt_packet, channels, max_fine_ts_width, full_ts_width):
self.write_underflow = Signal()
self.write_overflow = Signal()
self.write_sequence_error = Signal()
self.collision = Signal()
self.busy = Signal()
self.rt_packet = rt_packet
self.max_fine_ts_width = max_fine_ts_width
self.tsc = Signal(full_ts_width - max_fine_ts_width)
self.sync.rtio += \
If(rt_packet.tsc_load,
self.tsc.eq(rt_packet.tsc_load_value)
).Else(
self.tsc.eq(self.tsc + 1)
)
self.comb += rt_packet.tsc_input.eq(self.tsc)
self.sync.rio += [
self.write_underflow.eq(0),
self.write_overflow.eq(0),
self.collision.eq(0),
self.busy.eq(0)
]
for n, channel in enumerate(channels):
self.add_output(n, channel)
self.add_input(n, channel)
def add_output(self, n, channel):
rt_packet = self.rt_packet
max_fine_ts_width = self.max_fine_ts_width
interface = channel.interface.o
data_width = rtlink.get_data_width(interface)
address_width = rtlink.get_address_width(interface)
fine_ts_width = rtlink.get_fine_ts_width(interface)
assert fine_ts_width <= max_fine_ts_width
we = Signal()
self.comb += we.eq(rt_packet.write_stb
& (rt_packet.write_channel == n))
write_timestamp = rt_packet.write_timestamp[max_fine_ts_width-fine_ts_width:]
write_timestamp_coarse = rt_packet.write_timestamp[max_fine_ts_width:]
write_timestamp_fine = rt_packet.write_timestamp[max_fine_ts_width-fine_ts_width:max_fine_ts_width]
# latency compensation
if interface.delay:
tsc_comp = Signal.like(self.tsc)
self.sync.rtio += tsc_comp.eq(self.tsc - interface.delay + 1)
else:
tsc_comp = self.tsc
# FIFO
ev_layout = []
if data_width:
ev_layout.append(("data", data_width))
if address_width:
ev_layout.append(("address", address_width))
ev_layout.append(("timestamp", len(self.tsc) + fine_ts_width))
fifo = ClockDomainsRenamer("rio")(
SyncFIFOBuffered(layout_len(ev_layout), channel.ofifo_depth))
self.submodules += fifo
fifo_in = Record(ev_layout)
fifo_out = Record(ev_layout)
self.comb += [
fifo.din.eq(fifo_in.raw_bits()),
fifo_out.raw_bits().eq(fifo.dout)
]
# Buffer
buf_pending = Signal()
buf = Record(ev_layout)
buf_just_written = Signal()
# Special cases
replace = Signal()
sequence_error = Signal()
collision = Signal()
any_error = Signal()
if interface.enable_replace:
# Note: replace may be asserted at the same time as collision
# when addresses are different. In that case, it is a collision.
self.sync.rio += replace.eq(write_timestamp == buf.timestamp)
# Detect sequence errors on coarse timestamps only
# so that they are mutually exclusive with collision errors.
self.sync.rio += sequence_error.eq(write_timestamp_coarse < buf.timestamp[fine_ts_width:])
if interface.enable_replace:
if address_width:
different_addresses = rt_packet.write_address != buf.address
else:
different_addresses = 0
if fine_ts_width:
self.sync.rio += collision.eq(
(write_timestamp_coarse == buf.timestamp[fine_ts_width:])
& ((write_timestamp_fine != buf.timestamp[:fine_ts_width])
|different_addresses))
else:
self.sync.rio += collision.eq(
(write_timestamp == buf.timestamp) & different_addresses)
else:
self.sync.rio += collision.eq(
write_timestamp_coarse == buf.timestamp[fine_ts_width:])
self.comb += any_error.eq(sequence_error | collision)
self.sync.rio += [
If(we & sequence_error, self.write_sequence_error.eq(1)),
If(we & collision, self.collision.eq(1))
]
# Buffer read and FIFO write
self.comb += fifo_in.eq(buf)
in_guard_time = Signal()
self.comb += in_guard_time.eq(
buf.timestamp[fine_ts_width:] < tsc_comp + 4)
self.sync.rio += If(in_guard_time, buf_pending.eq(0))
report_underflow = Signal()
self.comb += \
If(buf_pending,
If(in_guard_time,
If(buf_just_written,
report_underflow.eq(1)
).Else(
fifo.we.eq(1)
)
),
If(we & ~replace & ~any_error,
fifo.we.eq(1)
)
)
self.sync.rio += If(report_underflow, self.write_underflow.eq(1))
# Buffer write
# Must come after read to handle concurrent read+write properly
self.sync.rio += [
buf_just_written.eq(0),
If(we & ~any_error,
buf_just_written.eq(1),
buf_pending.eq(1),
buf.timestamp.eq(write_timestamp),
buf.data.eq(rt_packet.write_data) if data_width else [],
buf.address.eq(rt_packet.write_address) if address_width else [],
),
If(we & ~fifo.writable, self.write_overflow.eq(1))
]
# FIFO level
self.sync.rio += \
If(rt_packet.fifo_space_update &
(rt_packet.fifo_space_channel == n),
rt_packet.fifo_space.eq(channel.ofifo_depth - fifo.level))
# FIFO read
self.sync.rio += [
fifo.re.eq(0),
interface.stb.eq(0),
If(fifo.readable &
(fifo_out.timestamp[fine_ts_width:] == tsc_comp),
fifo.re.eq(1),
interface.stb.eq(1)
)
]
if data_width:
self.sync.rio += interface.data.eq(fifo_out.data)
if address_width:
self.sync.rio += interface.address.eq(fifo_out.address)
if fine_ts_width:
self.sync.rio += interface.fine_ts.eq(fifo_out.timestamp[:fine_ts_width])
self.sync.rio += If(interface.stb & interface.busy, self.busy.eq(1))
def add_input(self, n, channel):
rt_packet = self.rt_packet
interface = channel.interface.i
if interface is None:
return
data_width = rtlink.get_data_width(interface)
fine_ts_width = rtlink.get_fine_ts_width(interface)
selected = Signal()
self.comb += selected.eq(rt_packet.read_channel == n)
# latency compensation
if interface.delay:
tsc_comp = Signal.like(self.tsc)
self.sync.rtio += tsc_comp.eq(self.tsc - interface.delay + 1)
else:
tsc_comp = self.tsc
# FIFO
ev_layout = []
if data_width:
ev_layout.append(("data", data_width))
if interface.timestamped:
ev_layout.append(("timestamp", len(self.tsc) + fine_ts_width))
fifo = ClockDomainsRenamer("rio")(
SyncFIFOBuffered(layout_len(ev_layout), channel.ififo_depth))
self.submodules += fifo
fifo_in = Record(ev_layout)
fifo_out = Record(ev_layout)
self.comb += [
fifo.din.eq(fifo_in.raw_bits()),
fifo_out.raw_bits().eq(fifo.dout)
]
# FIFO write
if data_width:
self.comb += fifo_in.data.eq(interface.data)
if interface.timestamped:
if fine_ts_width:
full_ts = Cat(interface.fine_ts, tsc_comp)
else:
full_ts = tsc_comp
self.comb += fifo_in.timestamp.eq(full_ts)
self.comb += fifo.we.eq(interface.stb)
overflow = Signal()
self.comb += If(selected, rt_packet.read_overflow.eq(overflow))
self.sync.rio += [
If(selected & rt_packet.read_overflow_ack, overflow.eq(0)),
If(fifo.we & ~fifo.writable, overflow.eq(1))
]
# FIFO read
if data_width:
self.comb += If(selected, rt_packet.read_data.eq(fifo_out.data))
if interface.timestamped:
self.comb += If(selected, rt_packet.read_timestamp.eq(fifo_out.timestamp))
self.comb += [
If(selected,
rt_packet.read_readable.eq(fifo.readable),
fifo.re.eq(rt_packet.read_consume)
)
]

View File

@ -66,12 +66,12 @@ class RTPacketMaster(Module):
# standard request interface
#
# notwrite=1 address=0 FIFO space request <channel>
# notwrite=1 address=0 buffer space request
# notwrite=1 address=1 read request <channel, timestamp>
#
# optimized for write throughput
# requests are performed on the DRTIO link preserving their order of issue
# this is important for FIFO space requests, which have to be ordered
# this is important for buffer space requests, which have to be ordered
# wrt writes.
self.sr_stb = Signal()
self.sr_ack = Signal()
@ -81,10 +81,10 @@ class RTPacketMaster(Module):
self.sr_address = Signal(16)
self.sr_data = Signal(512)
# fifo space reply interface
self.fifo_space_not = Signal()
self.fifo_space_not_ack = Signal()
self.fifo_space = Signal(16)
# buffer space reply interface
self.buffer_space_not = Signal()
self.buffer_space_not_ack = Signal()
self.buffer_space = Signal(16)
# read reply interface
self.read_not = Signal()
@ -209,11 +209,11 @@ class RTPacketMaster(Module):
)
# CDC
fifo_space_not = Signal()
fifo_space = Signal(16)
buffer_space_not = Signal()
buffer_space = Signal(16)
self.submodules += _CrossDomainNotification("rtio_rx",
fifo_space_not, fifo_space,
self.fifo_space_not, self.fifo_space_not_ack, self.fifo_space)
buffer_space_not, buffer_space,
self.buffer_space_not, self.buffer_space_not_ack, self.buffer_space)
set_time_stb = Signal()
set_time_ack = Signal()
@ -274,7 +274,7 @@ class RTPacketMaster(Module):
If(sr_buf_readable,
If(sr_notwrite,
Case(sr_address[0], {
0: NextState("FIFO_SPACE"),
0: NextState("BUFFER_SPACE"),
1: NextState("READ")
}),
).Else(
@ -316,8 +316,8 @@ class RTPacketMaster(Module):
NextState("IDLE")
)
)
tx_fsm.act("FIFO_SPACE",
tx_dp.send("fifo_space_request", channel=sr_channel),
tx_fsm.act("BUFFER_SPACE",
tx_dp.send("buffer_space_request"),
If(tx_dp.packet_last,
sr_buf_re.eq(1),
NextState("IDLE")
@ -369,7 +369,7 @@ class RTPacketMaster(Module):
If(rx_dp.packet_last,
Case(rx_dp.packet_type, {
rx_plm.types["echo_reply"]: echo_received_now.eq(1),
rx_plm.types["fifo_space_reply"]: NextState("FIFO_SPACE"),
rx_plm.types["buffer_space_reply"]: NextState("BUFFER_SPACE"),
rx_plm.types["read_reply"]: NextState("READ_REPLY"),
rx_plm.types["read_reply_noevent"]: NextState("READ_REPLY_NOEVENT"),
"default": err_unknown_packet_type.i.eq(1)
@ -382,9 +382,9 @@ class RTPacketMaster(Module):
err_packet_truncated.i.eq(1)
)
)
rx_fsm.act("FIFO_SPACE",
fifo_space_not.eq(1),
fifo_space.eq(rx_dp.packet_as["fifo_space_reply"].space),
rx_fsm.act("BUFFER_SPACE",
buffer_space_not.eq(1),
buffer_space.eq(rx_dp.packet_as["buffer_space_reply"].space),
NextState("INPUT")
)
rx_fsm.act("READ_REPLY",

View File

@ -3,6 +3,7 @@
from migen import *
from migen.genlib.fsm import *
from artiq.gateware.rtio import cri
from artiq.gateware.drtio.rt_serializer import *
@ -13,30 +14,11 @@ class RTPacketSatellite(Module):
self.tsc_load = Signal()
self.tsc_load_value = Signal(64)
self.tsc_input = Signal(64)
self.reset = Signal(reset=1)
self.reset_phy = Signal(reset=1)
self.fifo_space_channel = Signal(16)
self.fifo_space_update = Signal()
self.fifo_space = Signal(16)
# write parameters are stable one cycle before stb is asserted,
# and when stb is asserted.
self.write_stb = Signal()
self.write_timestamp = Signal(64)
self.write_channel = Signal(16)
self.write_address = Signal(16)
self.write_data = Signal(512)
self.read_channel = Signal(16)
self.read_readable = Signal()
self.read_consume = Signal()
self.read_data = Signal(32)
self.read_timestamp = Signal(64)
self.read_overflow = Signal()
self.read_overflow_ack = Signal()
self.cri = cri.Interface()
# # #
@ -69,27 +51,49 @@ class RTPacketSatellite(Module):
# RX->TX
echo_req = Signal()
fifo_space_set = Signal()
fifo_space_req = Signal()
fifo_space_ack = Signal()
buffer_space_set = Signal()
buffer_space_req = Signal()
buffer_space_ack = Signal()
self.sync += [
If(fifo_space_ack, fifo_space_req.eq(0)),
If(fifo_space_set, fifo_space_req.eq(1)),
If(buffer_space_ack, buffer_space_req.eq(0)),
If(buffer_space_set, buffer_space_req.eq(1)),
]
buffer_space_update = Signal()
buffer_space = Signal(16)
self.sync += If(buffer_space_update, buffer_space.eq(self.cri.o_buffer_space))
load_read_request = Signal()
clear_read_request = Signal()
read_request_pending = Signal()
self.sync += [
If(clear_read_request | self.reset,
read_request_pending.eq(0)
),
If(load_read_request,
read_request_pending.eq(1),
)
]
# RX FSM
read = Signal()
self.comb += [
self.tsc_load_value.eq(
rx_dp.packet_as["set_time"].timestamp),
self.fifo_space_channel.eq(
rx_dp.packet_as["fifo_space_request"].channel),
self.write_timestamp.eq(
rx_dp.packet_as["write"].timestamp),
self.write_channel.eq(
rx_dp.packet_as["write"].channel),
self.write_address.eq(
If(load_read_request | read_request_pending,
self.cri.chan_sel.eq(
rx_dp.packet_as["read_request"].channel),
self.cri.timestamp.eq(
rx_dp.packet_as["read_request"].timeout)
).Else(
self.cri.chan_sel.eq(
rx_dp.packet_as["write"].channel),
self.cri.timestamp.eq(
rx_dp.packet_as["write"].timestamp)
),
self.cri.o_address.eq(
rx_dp.packet_as["write"].address),
self.write_data.eq(
self.cri.o_data.eq(
Cat(rx_dp.packet_as["write"].short_data, write_data_buffer)),
]
@ -100,26 +104,6 @@ class RTPacketSatellite(Module):
self.reset_phy.eq(reset_phy)
]
load_read_request = Signal()
clear_read_request = Signal()
read_request_pending = Signal()
read_request_time_limit = Signal(64)
read_request_timeout = Signal()
read_request_wait = Signal() # 1 cycle latency channel→(data,overflow) and time_limit→timeout
self.sync += [
If(clear_read_request | self.reset,
read_request_pending.eq(0)
),
read_request_wait.eq(0),
If(load_read_request,
read_request_pending.eq(1),
read_request_wait.eq(1),
self.read_channel.eq(rx_dp.packet_as["read_request"].channel),
read_request_time_limit.eq(rx_dp.packet_as["read_request"].timeout)
),
read_request_timeout.eq(self.tsc_input >= read_request_time_limit),
]
rx_fsm = FSM(reset_state="INPUT")
self.submodules += rx_fsm
@ -138,7 +122,7 @@ class RTPacketSatellite(Module):
rx_plm.types["set_time"]: NextState("SET_TIME"),
rx_plm.types["reset"]: NextState("RESET"),
rx_plm.types["write"]: NextState("WRITE"),
rx_plm.types["fifo_space_request"]: NextState("FIFO_SPACE"),
rx_plm.types["buffer_space_request"]: NextState("BUFFER_SPACE"),
rx_plm.types["read_request"]: NextState("READ_REQUEST"),
"default": self.unknown_packet_type.eq(1)
})
@ -165,7 +149,7 @@ class RTPacketSatellite(Module):
rx_fsm.act("WRITE",
If(write_data_buffer_cnt == rx_dp.packet_as["write"].extra_data_cnt,
self.write_stb.eq(1),
self.cri.cmd.eq(cri.commands["write"]),
NextState("INPUT")
).Else(
write_data_buffer_load.eq(1),
@ -175,14 +159,15 @@ class RTPacketSatellite(Module):
)
)
)
rx_fsm.act("FIFO_SPACE",
fifo_space_set.eq(1),
self.fifo_space_update.eq(1),
rx_fsm.act("BUFFER_SPACE",
buffer_space_set.eq(1),
buffer_space_update.eq(1),
NextState("INPUT")
)
rx_fsm.act("READ_REQUEST",
load_read_request.eq(1),
self.cri.cmd.eq(cri.commands["read"]),
NextState("INPUT")
)
@ -192,11 +177,11 @@ class RTPacketSatellite(Module):
tx_fsm.act("IDLE",
If(echo_req, NextState("ECHO")),
If(fifo_space_req, NextState("FIFO_SPACE")),
If(~read_request_wait & read_request_pending,
If(read_request_timeout, NextState("READ_TIMEOUT")),
If(self.read_overflow, NextState("READ_OVERFLOW")),
If(self.read_readable, NextState("READ"))
If(buffer_space_req, NextState("BUFFER_SPACE")),
If(read_request_pending,
If(~self.cri.i_status[2], NextState("READ")),
If(self.cri.i_status[0], NextState("READ_TIMEOUT")),
If(self.cri.i_status[1], NextState("READ_OVERFLOW"))
)
)
@ -205,9 +190,9 @@ class RTPacketSatellite(Module):
If(tx_dp.packet_last, NextState("IDLE"))
)
tx_fsm.act("FIFO_SPACE",
fifo_space_ack.eq(1),
tx_dp.send("fifo_space_reply", space=self.fifo_space),
tx_fsm.act("BUFFER_SPACE",
buffer_space_ack.eq(1),
tx_dp.send("buffer_space_reply", space=buffer_space),
If(tx_dp.packet_last, NextState("IDLE"))
)
@ -220,17 +205,15 @@ class RTPacketSatellite(Module):
tx_dp.send("read_reply_noevent", overflow=1),
clear_read_request.eq(1),
If(tx_dp.packet_last,
self.read_overflow_ack.eq(1),
NextState("IDLE")
)
)
tx_fsm.act("READ",
tx_dp.send("read_reply",
timestamp=self.read_timestamp,
data=self.read_data),
timestamp=self.cri.i_timestamp,
data=self.cri.i_data),
clear_read_request.eq(1),
If(tx_dp.packet_last,
self.read_consume.eq(1),
NextState("IDLE")
)
)

View File

@ -18,7 +18,7 @@ class PacketLayoutManager:
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
@ -54,7 +54,7 @@ def get_m2s_layouts(alignment):
("address", 16),
("extra_data_cnt", 8),
("short_data", short_data_len))
plm.add_type("fifo_space_request", ("channel", 16))
plm.add_type("buffer_space_request")
plm.add_type("read_request", ("channel", 16), ("timeout", 64))
@ -66,7 +66,7 @@ def get_s2m_layouts(alignment):
plm.add_type("echo_reply")
plm.add_type("fifo_space_reply", ("space", 16))
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
@ -110,7 +110,7 @@ class ReceiveDatapath(Module):
packet_buffer_count = Signal(max=w_in_packet+1)
self.sync += \
If(self.packet_buffer_load,
Case(packet_buffer_count,
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)

View File

@ -1,5 +1,6 @@
from artiq.gateware.rtio.cri import KernelInitiator, CRIInterconnectShared
from artiq.gateware.rtio.core import Channel, LogChannel, Core
from artiq.gateware.rtio.channel import Channel, LogChannel
from artiq.gateware.rtio.core import Core
from artiq.gateware.rtio.analyzer import Analyzer
from artiq.gateware.rtio.moninj import MonInj
from artiq.gateware.rtio.dma import DMA

View File

@ -94,10 +94,6 @@ class MessageEncoder(Module, AutoCSR):
exception_stb.eq(1),
exception.exception_type.eq(ExceptionType.o_underflow.value)
),
If(just_written & cri.o_status[2],
exception_stb.eq(1),
exception.exception_type.eq(ExceptionType.o_sequence_error.value)
),
If(read_overflow,
exception_stb.eq(1),
exception.exception_type.eq(ExceptionType.i_overflow.value)

View File

@ -2,7 +2,7 @@ from migen import *
from migen.genlib.cdc import *
__all__ = ["GrayCodeTransfer", "RTIOCounter", "BlindTransfer"]
__all__ = ["GrayCodeTransfer", "BlindTransfer"]
# note: transfer is in rtio/sys domains and not affected by the reset CSRs
@ -28,28 +28,15 @@ class GrayCodeTransfer(Module):
self.sync += self.o.eq(value_sys)
class RTIOCounter(Module):
def __init__(self, width):
self.width = width
# Timestamp counter in RTIO domain
self.value_rtio = Signal(width)
# Timestamp counter resynchronized to sys domain
# Lags behind value_rtio, monotonic and glitch-free
self.value_sys = Signal(width)
# # #
# note: counter is in rtio domain and never affected by the reset CSRs
self.sync.rtio += self.value_rtio.eq(self.value_rtio + 1)
gt = GrayCodeTransfer(width)
self.submodules += gt
self.comb += gt.i.eq(self.value_rtio), self.value_sys.eq(gt.o)
class BlindTransfer(Module):
def __init__(self, idomain="rio", odomain="rsys"):
def __init__(self, idomain="rio", odomain="rsys", data_width=0):
self.i = Signal()
self.o = Signal()
if data_width:
self.data_i = Signal(data_width)
self.data_o = Signal(data_width)
# # #
ps = PulseSynchronizer(idomain, odomain)
ps_ack = PulseSynchronizer(odomain, idomain)
@ -65,3 +52,10 @@ class BlindTransfer(Module):
ps_ack.i.eq(ps.o),
self.o.eq(ps.o)
]
if data_width:
bxfer_data = Signal(data_width)
isync += If(ps.i, bxfer_data.eq(self.data_i))
bxfer_data.attr.add("no_retiming")
self.specials += MultiReg(bxfer_data, self.data_o,
odomain=odomain)

View File

@ -0,0 +1,36 @@
import warnings
from artiq.gateware.rtio import rtlink
class Channel:
def __init__(self, interface, probes=None, overrides=None,
ofifo_depth=None, ififo_depth=64):
if probes is None:
probes = []
if overrides is None:
overrides = []
self.interface = interface
self.probes = probes
self.overrides = overrides
if ofifo_depth is None:
ofifo_depth = 64
else:
warnings.warn("ofifo_depth is deprecated", DeprecationWarning)
self.ofifo_depth = ofifo_depth
self.ififo_depth = ififo_depth
@classmethod
def from_phy(cls, phy, **kwargs):
probes = getattr(phy, "probes", [])
overrides = getattr(phy, "overrides", [])
return cls(phy.rtlink, probes, overrides, **kwargs)
class LogChannel:
"""A degenerate channel used to log messages into the analyzer."""
def __init__(self):
self.interface = rtlink.Interface(rtlink.OInterface(32))
self.probes = []
self.overrides = []

View File

@ -2,302 +2,31 @@ from functools import reduce
from operator import and_
from migen import *
from migen.genlib.record import Record
from migen.genlib.fifo import AsyncFIFO
from migen.genlib.resetsync import AsyncResetSynchronizer
from misoc.interconnect.csr import *
from artiq.gateware.rtio import cri, rtlink
from artiq.gateware.rtio import cri
from artiq.gateware.rtio import rtlink
from artiq.gateware.rtio.channel import *
from artiq.gateware.rtio.cdc import *
# CHOOSING A GUARD TIME
#
# The buffer must be transferred to the FIFO soon enough to account for:
# * transfer of counter to sys domain: Tio + 2*Tsys + Tsys
# * FIFO latency: Tsys + 2*Tio
# * FIFO buffer latency: Tio
# Therefore we must choose:
# guard_io_cycles > (4*Tio + 4*Tsys)/Tio
#
# We are writing to the FIFO from the buffer when the guard time has been
# reached. This can fill the FIFO and deassert the writable flag. A race
# condition occurs that causes problems if the deassertion happens between
# the CPU checking the writable flag (and reading 1) and writing a new event.
#
# When the FIFO is about to be full, it contains fifo_depth-1 events of
# strictly increasing timestamps.
#
# Thus the FIFO-filling event's timestamp must satisfy:
# timestamp*Tio > (fifo_depth-1)*Tio + time
# We also have (guard time reached):
# timestamp*Tio < time + guard_io_cycles*Tio
# [NB: time > counter.value_sys*Tio]
# Thus we must have:
# guard_io_cycles > fifo_depth-1
#
# We can prevent overflows by choosing instead:
# guard_io_cycles < fifo_depth-1
class _OutputManager(Module):
def __init__(self, interface, counter, fifo_depth, guard_io_cycles):
data_width = rtlink.get_data_width(interface)
address_width = rtlink.get_address_width(interface)
fine_ts_width = rtlink.get_fine_ts_width(interface)
ev_layout = []
if data_width:
ev_layout.append(("data", data_width))
if address_width:
ev_layout.append(("address", address_width))
ev_layout.append(("timestamp", counter.width + fine_ts_width))
# ev must be valid 1 cycle before we to account for the latency in
# generating replace, sequence_error and collision
self.ev = Record(ev_layout)
self.writable = Signal()
self.we = Signal() # maximum throughput 1/2
self.underflow = Signal() # valid 1 cycle after we, pulsed
self.sequence_error = Signal()
self.collision = Signal()
self.busy = Signal() # pulsed
# # #
# FIFO
fifo = ClockDomainsRenamer({"write": "rsys", "read": "rio"})(
AsyncFIFO(layout_len(ev_layout), fifo_depth))
self.submodules += fifo
fifo_in = Record(ev_layout)
fifo_out = Record(ev_layout)
self.comb += [
fifo.din.eq(fifo_in.raw_bits()),
fifo_out.raw_bits().eq(fifo.dout)
]
# Buffer
buf_pending = Signal()
buf = Record(ev_layout)
buf_just_written = Signal()
# Special cases
replace = Signal(reset_less=True)
sequence_error = Signal(reset_less=True)
collision = Signal(reset_less=True)
any_error = Signal()
if interface.enable_replace:
# Note: replace may be asserted at the same time as collision
# when addresses are different. In that case, it is a collision.
self.sync.rsys += replace.eq(self.ev.timestamp == buf.timestamp)
# Detect sequence errors on coarse timestamps only
# so that they are mutually exclusive with collision errors.
self.sync.rsys += sequence_error.eq(self.ev.timestamp[fine_ts_width:] <
buf.timestamp[fine_ts_width:])
if interface.enable_replace:
if address_width:
different_addresses = self.ev.address != buf.address
else:
different_addresses = 0
if fine_ts_width:
self.sync.rsys += collision.eq(
(self.ev.timestamp[fine_ts_width:] == buf.timestamp[fine_ts_width:])
& ((self.ev.timestamp[:fine_ts_width] != buf.timestamp[:fine_ts_width])
|different_addresses))
else:
self.sync.rsys += collision.eq(
(self.ev.timestamp == buf.timestamp) & different_addresses)
else:
self.sync.rsys += collision.eq(
self.ev.timestamp[fine_ts_width:] == buf.timestamp[fine_ts_width:])
self.comb += [
any_error.eq(sequence_error | collision),
self.sequence_error.eq(self.we & sequence_error),
self.collision.eq(self.we & collision)
]
# Buffer read and FIFO write
self.comb += fifo_in.eq(buf)
in_guard_time = Signal()
self.comb += in_guard_time.eq(
buf.timestamp[fine_ts_width:]
< counter.value_sys + guard_io_cycles)
self.sync.rsys += If(in_guard_time, buf_pending.eq(0))
self.comb += \
If(buf_pending,
If(in_guard_time,
If(buf_just_written,
self.underflow.eq(1)
).Else(
fifo.we.eq(1)
)
),
If(self.we & ~replace & ~any_error,
fifo.we.eq(1)
)
)
# Buffer write
# Must come after read to handle concurrent read+write properly
self.sync.rsys += [
buf_just_written.eq(0),
If(self.we & ~any_error,
buf_just_written.eq(1),
buf_pending.eq(1),
buf.eq(self.ev)
)
]
self.comb += self.writable.eq(fifo.writable)
# Buffer output of FIFO to improve timing
dout_stb = Signal()
dout_ack = Signal()
dout = Record(ev_layout)
self.sync.rio += \
If(fifo.re,
dout_stb.eq(1),
dout.eq(fifo_out)
).Elif(dout_ack,
dout_stb.eq(0)
)
self.comb += fifo.re.eq(fifo.readable & (~dout_stb | dout_ack))
# latency compensation
if interface.delay:
counter_rtio = Signal.like(counter.value_rtio, reset_less=True)
self.sync.rtio += counter_rtio.eq(counter.value_rtio -
(interface.delay + 1))
else:
counter_rtio = counter.value_rtio
# FIFO read through buffer
self.comb += [
dout_ack.eq(
dout.timestamp[fine_ts_width:] == counter_rtio),
interface.stb.eq(dout_stb & dout_ack)
]
busy_transfer = BlindTransfer()
self.submodules += busy_transfer
self.comb += [
busy_transfer.i.eq(interface.stb & interface.busy),
self.busy.eq(busy_transfer.o),
]
if data_width:
self.comb += interface.data.eq(dout.data)
if address_width:
self.comb += interface.address.eq(dout.address)
if fine_ts_width:
self.comb += interface.fine_ts.eq(dout.timestamp[:fine_ts_width])
class _InputManager(Module):
def __init__(self, interface, counter, fifo_depth):
data_width = rtlink.get_data_width(interface)
fine_ts_width = rtlink.get_fine_ts_width(interface)
ev_layout = []
if data_width:
ev_layout.append(("data", data_width))
if interface.timestamped:
ev_layout.append(("timestamp", counter.width + fine_ts_width))
self.ev = Record(ev_layout)
self.readable = Signal()
self.re = Signal()
self.overflow = Signal() # pulsed
# # #
fifo = ClockDomainsRenamer({"read": "rsys", "write": "rio"})(
AsyncFIFO(layout_len(ev_layout), fifo_depth))
self.submodules += fifo
fifo_in = Record(ev_layout)
fifo_out = Record(ev_layout)
self.comb += [
fifo.din.eq(fifo_in.raw_bits()),
fifo_out.raw_bits().eq(fifo.dout)
]
# latency compensation
if interface.delay:
counter_rtio = Signal.like(counter.value_rtio, reset_less=True)
self.sync.rtio += counter_rtio.eq(counter.value_rtio -
(interface.delay + 1))
else:
counter_rtio = counter.value_rtio
# FIFO write
if data_width:
self.comb += fifo_in.data.eq(interface.data)
if interface.timestamped:
if fine_ts_width:
full_ts = Cat(interface.fine_ts, counter_rtio)
else:
full_ts = counter_rtio
self.comb += fifo_in.timestamp.eq(full_ts)
self.comb += fifo.we.eq(interface.stb)
# FIFO read
self.comb += [
self.ev.eq(fifo_out),
self.readable.eq(fifo.readable),
fifo.re.eq(self.re)
]
overflow_transfer = BlindTransfer()
self.submodules += overflow_transfer
self.comb += [
overflow_transfer.i.eq(fifo.we & ~fifo.writable),
self.overflow.eq(overflow_transfer.o),
]
class Channel:
def __init__(self, interface, probes=None, overrides=None,
ofifo_depth=64, ififo_depth=64):
if probes is None:
probes = []
if overrides is None:
overrides = []
self.interface = interface
self.probes = probes
self.overrides = overrides
self.ofifo_depth = ofifo_depth
self.ififo_depth = ififo_depth
@classmethod
def from_phy(cls, phy, **kwargs):
probes = getattr(phy, "probes", [])
overrides = getattr(phy, "overrides", [])
return cls(phy.rtlink, probes, overrides, **kwargs)
class LogChannel:
"""A degenerate channel used to log messages into the analyzer."""
def __init__(self):
self.interface = rtlink.Interface(rtlink.OInterface(32))
self.probes = []
self.overrides = []
from artiq.gateware.rtio.sed.core import *
from artiq.gateware.rtio.input_collector import *
class Core(Module, AutoCSR):
def __init__(self, channels, fine_ts_width=None, guard_io_cycles=20):
if fine_ts_width is None:
fine_ts_width = max(rtlink.get_fine_ts_width(c.interface)
for c in channels)
def __init__(self, channels, lane_count=8, fifo_depth=128,
glbl_fine_ts_width=None):
self.cri = cri.Interface()
self.reset = CSR()
self.reset_phy = CSR()
self.async_error = CSR(2)
self.async_error = CSR(3)
self.collision_channel = CSRStatus(16)
self.busy_channel = CSRStatus(16)
self.sequence_error_channel = CSRStatus(16)
# Clocking/Reset
# Create rsys, rio and rio_phy domains based on sys and rtio
# with reset controlled by CRI.
# with reset controlled by CSR.
#
# The `rio` CD contains logic that is reset with `core.reset()`.
# That's state that could unduly affect subsequent experiments,
@ -327,125 +56,78 @@ class Core(Module, AutoCSR):
self.specials += AsyncResetSynchronizer(self.cd_rio, cmd_reset)
self.specials += AsyncResetSynchronizer(self.cd_rio_phy, cmd_reset_phy)
# Managers
self.submodules.counter = RTIOCounter(len(self.cri.timestamp) - fine_ts_width)
# TSC
chan_fine_ts_width = max(max(rtlink.get_fine_ts_width(channel.interface.o)
for channel in channels),
max(rtlink.get_fine_ts_width(channel.interface.i)
for channel in channels))
if glbl_fine_ts_width is None:
glbl_fine_ts_width = chan_fine_ts_width
assert glbl_fine_ts_width >= chan_fine_ts_width
# Collision is not an asynchronous error with local RTIO, but
# we treat it as such for consistency with DRTIO, where collisions
# are reported by the satellites.
o_underflow = Signal()
o_sequence_error = Signal()
coarse_ts = Signal(64-glbl_fine_ts_width)
self.sync.rtio += coarse_ts.eq(coarse_ts + 1)
coarse_ts_cdc = GrayCodeTransfer(len(coarse_ts))
self.submodules += coarse_ts_cdc
self.comb += [
coarse_ts_cdc.i.eq(coarse_ts),
self.cri.counter.eq(coarse_ts_cdc.o << glbl_fine_ts_width)
]
# Outputs/Inputs
quash_channels = [n for n, c in enumerate(channels) if isinstance(c, LogChannel)]
outputs = SED(channels, glbl_fine_ts_width, "async",
quash_channels=quash_channels,
lane_count=lane_count, fifo_depth=fifo_depth,
interface=self.cri)
self.submodules += outputs
self.comb += outputs.coarse_timestamp.eq(coarse_ts)
self.sync += outputs.minimum_coarse_timestamp.eq(coarse_ts + 16)
inputs = InputCollector(channels, glbl_fine_ts_width, "async",
quash_channels=quash_channels,
interface=self.cri)
self.submodules += inputs
self.comb += inputs.coarse_timestamp.eq(coarse_ts)
# Asychronous output errors
o_collision_sync = BlindTransfer(data_width=16)
o_busy_sync = BlindTransfer(data_width=16)
self.submodules += o_collision_sync, o_busy_sync
o_collision = Signal()
o_busy = Signal()
self.sync.rsys += [
If(self.cri.cmd == cri.commands["write"],
o_underflow.eq(0),
o_sequence_error.eq(0),
)
]
o_sequence_error = Signal()
self.sync += [
If(self.async_error.re,
If(self.async_error.r[0], o_collision.eq(0)),
If(self.async_error.r[1], o_busy.eq(0)),
If(self.async_error.r[2], o_sequence_error.eq(0)),
),
If(o_collision_sync.o,
o_collision.eq(1),
If(~o_collision,
self.collision_channel.status.eq(o_collision_sync.data_o)
)
),
If(o_busy_sync.o,
o_busy.eq(1),
If(~o_busy,
self.busy_channel.status.eq(o_busy_sync.data_o)
)
),
If(outputs.sequence_error,
o_sequence_error.eq(1),
If(~o_sequence_error,
self.sequence_error_channel.status.eq(outputs.sequence_error_channel)
)
)
]
self.comb += self.async_error.w.eq(Cat(o_collision, o_busy, o_sequence_error))
o_statuses, i_statuses = [], []
i_datas, i_timestamps = [], []
i_ack = Signal()
sel = self.cri.chan_sel[:16]
for n, channel in enumerate(channels):
if isinstance(channel, LogChannel):
o_statuses.append(1)
i_datas.append(0)
i_timestamps.append(0)
i_statuses.append(0)
continue
selected = Signal()
self.comb += selected.eq(sel == n)
o_manager = _OutputManager(channel.interface.o, self.counter,
channel.ofifo_depth, guard_io_cycles)
self.submodules += o_manager
if hasattr(o_manager.ev, "data"):
self.comb += o_manager.ev.data.eq(self.cri.o_data)
if hasattr(o_manager.ev, "address"):
self.comb += o_manager.ev.address.eq(self.cri.o_address)
ts_shift = len(self.cri.timestamp) - len(o_manager.ev.timestamp)
self.comb += o_manager.ev.timestamp.eq(self.cri.timestamp[ts_shift:])
self.comb += o_manager.we.eq(selected & (self.cri.cmd == cri.commands["write"]))
self.sync.rsys += [
If(o_manager.underflow, o_underflow.eq(1)),
If(o_manager.sequence_error, o_sequence_error.eq(1))
]
self.sync += [
If(o_manager.collision, o_collision.eq(1)),
If(o_manager.busy, o_busy.eq(1))
]
o_statuses.append(o_manager.writable)
if channel.interface.i is not None:
i_manager = _InputManager(channel.interface.i, self.counter,
channel.ififo_depth)
self.submodules += i_manager
if hasattr(i_manager.ev, "data"):
i_datas.append(i_manager.ev.data)
else:
i_datas.append(0)
if channel.interface.i.timestamped:
ts_shift = (len(self.cri.i_timestamp) - len(i_manager.ev.timestamp))
i_timestamps.append(i_manager.ev.timestamp << ts_shift)
else:
i_timestamps.append(0)
overflow = Signal()
self.sync.rsys += [
If(selected & i_ack,
overflow.eq(0)),
If(i_manager.overflow,
overflow.eq(1))
]
self.comb += i_manager.re.eq(selected & i_ack & ~overflow)
i_statuses.append(Cat(i_manager.readable & ~overflow, overflow))
else:
i_datas.append(0)
i_timestamps.append(0)
i_statuses.append(0)
o_status_raw = Signal()
self.comb += [
o_status_raw.eq(Array(o_statuses)[sel]),
self.cri.o_status.eq(Cat(
~o_status_raw, o_underflow, o_sequence_error)),
self.async_error.w.eq(Cat(o_collision, o_busy))
o_collision_sync.i.eq(outputs.collision),
o_collision_sync.data_i.eq(outputs.collision_channel),
o_busy_sync.i.eq(outputs.busy),
o_busy_sync.data_i.eq(outputs.busy_channel)
]
i_status_raw = Signal(2)
self.comb += i_status_raw.eq(Array(i_statuses)[sel])
input_timeout = Signal.like(self.cri.timestamp)
input_pending = Signal()
self.sync.rsys += [
i_ack.eq(0),
If(i_ack,
self.cri.i_status.eq(Cat(~i_status_raw[0], i_status_raw[1], 0)),
self.cri.i_data.eq(Array(i_datas)[sel]),
self.cri.i_timestamp.eq(Array(i_timestamps)[sel]),
),
If((self.cri.counter >= input_timeout) | (i_status_raw != 0),
If(input_pending, i_ack.eq(1)),
input_pending.eq(0)
),
If(self.cri.cmd == cri.commands["read"],
input_timeout.eq(self.cri.timestamp),
input_pending.eq(1),
self.cri.i_status.eq(0b100)
)
]
self.comb += self.cri.counter.eq(self.counter.value_sys << fine_ts_width)

View File

@ -25,8 +25,11 @@ layout = [
("o_data", 512, DIR_M_TO_S),
("o_address", 16, DIR_M_TO_S),
# o_status bits:
# <0:wait> <1:underflow> <2:sequence_error>
("o_status", 3, DIR_S_TO_M),
# <0:wait> <1:underflow>
("o_status", 2, DIR_S_TO_M),
# targets may optionally report a pessimistic estimate of the number
# of outputs events that can be written without waiting.
("o_buffer_space", 16, DIR_S_TO_M),
("i_data", 32, DIR_S_TO_M),
("i_timestamp", 64, DIR_S_TO_M),
@ -35,6 +38,9 @@ layout = [
# <0> and <1> are mutually exclusive. <1> has higher priority.
("i_status", 3, DIR_S_TO_M),
# value of the timestamp counter transferred into the CRI clock domain.
# monotonic, may lag behind the counter in the IO clock domain, but
# not be ahead of it.
("counter", 64, DIR_S_TO_M)
]
@ -55,7 +61,7 @@ class KernelInitiator(Module, AutoCSR):
self.o_data = CSRStorage(512, write_from_dev=True)
self.o_address = CSRStorage(16)
self.o_we = CSR()
self.o_status = CSRStatus(3)
self.o_status = CSRStatus(2)
self.i_data = CSRStatus(32)
self.i_timestamp = CSRStatus(64)

View File

@ -242,9 +242,7 @@ class TimeOffset(Module, AutoCSR):
class CRIMaster(Module, AutoCSR):
def __init__(self):
self.error_status = CSRStatus(3) # same encoding as RTIO status
self.error_underflow_reset = CSR()
self.error_sequence_error_reset = CSR()
self.underflow = CSR()
self.error_channel = CSRStatus(24)
self.error_timestamp = CSRStatus(64)
@ -256,19 +254,16 @@ class CRIMaster(Module, AutoCSR):
# # #
error_set = Signal(2)
for i, rcsr in enumerate([self.error_underflow_reset, self.error_sequence_error_reset]):
# bit 0 is RTIO wait and always 0 here
bit = i + 1
self.sync += [
If(error_set[i],
self.error_status.status[bit].eq(1),
self.error_channel.status.eq(self.sink.channel),
self.error_timestamp.status.eq(self.sink.timestamp),
self.error_address.status.eq(self.sink.address)
),
If(rcsr.re, self.error_status.status[bit].eq(0))
]
underflow_trigger = Signal()
self.sync += [
If(underflow_trigger,
self.underflow.w.eq(1),
self.error_channel.status.eq(self.sink.channel),
self.error_timestamp.status.eq(self.sink.timestamp),
self.error_address.status.eq(self.sink.address)
),
If(self.underflow.re, self.underflow.w.eq(0))
]
self.comb += [
self.cri.chan_sel.eq(self.sink.channel),
@ -281,7 +276,7 @@ class CRIMaster(Module, AutoCSR):
self.submodules += fsm
fsm.act("IDLE",
If(self.error_status.status == 0,
If(~self.underflow.w,
If(self.sink.stb,
If(self.sink.eop,
# last packet contains dummy data, discard it
@ -306,16 +301,14 @@ class CRIMaster(Module, AutoCSR):
self.sink.ack.eq(1),
NextState("IDLE")
),
If(self.cri.o_status[1], NextState("UNDERFLOW")),
If(self.cri.o_status[2], NextState("SEQUENCE_ERROR"))
If(self.cri.o_status[1], NextState("UNDERFLOW"))
)
fsm.act("UNDERFLOW",
self.busy.eq(1),
underflow_trigger.eq(1),
self.sink.ack.eq(1),
NextState("IDLE")
)
for n, name in enumerate(["UNDERFLOW", "SEQUENCE_ERROR"]):
fsm.act(name,
self.busy.eq(1),
error_set.eq(1 << n),
self.sink.ack.eq(1),
NextState("IDLE")
)
class DMA(Module):

View File

@ -0,0 +1,140 @@
from migen import *
from migen.genlib.record import Record
from migen.genlib.fifo import *
from artiq.gateware.rtio import cri
from artiq.gateware.rtio import rtlink
from artiq.gateware.rtio.cdc import *
__all__ = ["InputCollector"]
def get_channel_layout(coarse_ts_width, interface):
data_width = rtlink.get_data_width(interface)
fine_ts_width = rtlink.get_fine_ts_width(interface)
layout = []
if data_width:
layout.append(("data", data_width))
if interface.timestamped:
layout.append(("timestamp", coarse_ts_width + fine_ts_width))
return layout
class InputCollector(Module):
def __init__(self, channels, glbl_fine_ts_width, mode, quash_channels=[], interface=None):
if interface is None:
interface = cri.Interface()
self.cri = interface
self.coarse_timestamp = Signal(64 - glbl_fine_ts_width)
# # #
if mode == "sync":
fifo_factory = SyncFIFOBuffered
sync_io = self.sync
sync_cri = self.sync
elif mode == "async":
fifo_factory = lambda *args: ClockDomainsRenamer({"write": "rio", "read": "rsys"})(AsyncFIFO(*args))
sync_io = self.sync.rio
sync_cri = self.sync.rsys
else:
raise ValueError
i_statuses, i_datas, i_timestamps = [], [], []
i_ack = Signal()
sel = self.cri.chan_sel[:16]
for n, channel in enumerate(channels):
iif = channel.interface.i
if iif is None or n in quash_channels:
i_datas.append(0)
i_timestamps.append(0)
i_statuses.append(0)
continue
# FIFO
layout = get_channel_layout(len(self.coarse_timestamp), iif)
fifo = fifo_factory(layout_len(layout), channel.ififo_depth)
self.submodules += fifo
fifo_in = Record(layout)
fifo_out = Record(layout)
self.comb += [
fifo.din.eq(fifo_in.raw_bits()),
fifo_out.raw_bits().eq(fifo.dout)
]
# FIFO write
if iif.delay:
counter_rtio = Signal.like(self.coarse_timestamp, reset_less=True)
sync_io += counter_rtio.eq(self.coarse_timestamp - (iif.delay + 1))
else:
counter_rtio = self.coarse_timestamp
if hasattr(fifo_in, "data"):
self.comb += fifo_in.data.eq(iif.data)
if hasattr(fifo_in, "timestamp"):
if hasattr(iif, "fine_ts"):
full_ts = Cat(iif.fine_ts, counter_rtio)
else:
full_ts = counter_rtio
self.comb += fifo_in.timestamp.eq(full_ts)
self.comb += fifo.we.eq(iif.stb)
overflow_io = Signal()
self.comb += overflow_io.eq(fifo.we & ~fifo.writable)
if mode == "sync":
overflow_trigger = overflow_io
elif mode == "async":
overflow_transfer = BlindTransfer()
self.submodules += overflow_transfer
self.comb += overflow_transfer.i.eq(overflow_io)
overflow_trigger = overflow_transfer.o
else:
raise ValueError
# FIFO read, CRI connection
if hasattr(fifo_out, "data"):
i_datas.append(fifo_out.data)
else:
i_datas.append(0)
if hasattr(fifo_out, "timestamp"):
ts_shift = 64 - len(fifo_out.timestamp)
i_timestamps.append(fifo_out.timestamp << ts_shift)
else:
i_timestamps.append(0)
selected = Signal()
self.comb += selected.eq(sel == n)
overflow = Signal()
sync_cri += [
If(selected & i_ack,
overflow.eq(0)),
If(overflow_trigger,
overflow.eq(1))
]
self.comb += fifo.re.eq(selected & i_ack & ~overflow)
i_statuses.append(Cat(fifo.readable & ~overflow, overflow))
i_status_raw = Signal(2)
self.comb += i_status_raw.eq(Array(i_statuses)[sel])
input_timeout = Signal.like(self.cri.timestamp)
input_pending = Signal()
sync_cri += [
i_ack.eq(0),
If(i_ack,
self.cri.i_status.eq(Cat(~i_status_raw[0], i_status_raw[1], 0)),
self.cri.i_data.eq(Array(i_datas)[sel]),
self.cri.i_timestamp.eq(Array(i_timestamps)[sel]),
),
If((self.cri.counter >= input_timeout) | (i_status_raw != 0),
If(input_pending, i_ack.eq(1)),
input_pending.eq(0)
),
If(self.cri.cmd == cri.commands["read"],
input_timeout.eq(self.cri.timestamp),
input_pending.eq(1),
self.cri.i_status.eq(0b100)
)
]

View File

@ -69,14 +69,13 @@ class Interface:
def _get_or_zero(interface, attr):
if isinstance(interface, Interface):
return max(_get_or_zero(interface.i, attr),
_get_or_zero(interface.o, attr))
if interface is None:
return 0
assert isinstance(interface, (OInterface, IInterface))
if hasattr(interface, attr):
return len(getattr(interface, attr))
else:
if hasattr(interface, attr):
return len(getattr(interface, attr))
else:
return 0
return 0
def get_data_width(interface):

View File

@ -0,0 +1,57 @@
"""
The traditional RTIO system used one dedicated FIFO per output channel. While this architecture
is simple and appropriate for ARTIQ systems that were rather small and simple, it shows limitations
on more complex ones. By decreasing importance:
* with DRTIO, the master needed to keep track, for each FIFO in each satellite, a lower bound on
the number of available entries plus the last timestamp written. The timestamp is stored in order
to detect sequence errors rapidly (and allow precise exceptions without compromising performance).
When many satellites are involved, especially with DRTIO switches, the storage requirements become
prohibitive.
* with many channels in one device, the large muxes and the error detection logic that
can handle all the FIFOs make timing closure problematic.
* with many channels in one device, the FIFOs waste FPGA space, as they are never all filled at the
same time.
The scalable event dispatcher (SED) addresses those issues:
* only one lower bound on the available entries needs to be stored per satellite device for flow
control purposes (called "buffer space"). Most sequence errors no longer exist (non-increasing
timestamps into one channel are permitted to an extent) so rapid detection of them is no longer
required.
* the events can be demultiplexed to the different channels using pipeline stages that ease timing.
* only a few FIFOs are required and they are shared between the channels.
The SED core contains a configurable number of FIFOs that hold the usual information about RTIO
events (timestamp, address, data), the channel number, and a sequence number. The sequence number is
increased for each event submitted.
When an event is submitted, it is written into the current FIFO if its timestamp is strictly
increasing. Otherwise, the current FIFO number is incremented by one (and wraps around, if the
current FIFO was the last) and the event is written there, unless that FIFO already contains an
event with a greater timestamp. In that case, an asynchronous error is reported. If the destination
FIFO is full, the submitter is blocked.
In order to help spreading events among FIFOs and maximize buffering, the SED core may optionally
also switch to the next FIFO after the current FIFO has been full.
At the output of the FIFOs, the events are distributed to the channels and simultaneous events on
the same channel are handled using a structure similar to a odd-even merge-sort network that sorts
by channel. When there are simultaneous events on the same channel, the event with the highest
sequence number is kept and a flag is raised to indicate that a replacement occured on that
channel. If a replacement was made on a channel that has replacements disabled, the final
event is dropped and a collision error is reported asynchronously.
Underflow errors are detected as before by comparing the event timestamp with the current value of
the counter, and dropping events that do not have enough time to make it through the system.
The sequence number is sized to be able to represent the combined capacity of all FIFOs, plus
2 bits that allow the detection of wrap-arounds.
The maximum number of simultaneous events (on different channels), and the maximum number of active
timeline "rewinds", are equal to the number of FIFOs.
The SED logic support both synchronous and asynchronous FIFOs, which are used respectively for local
RTIO and DRTIO.
To implement flow control in DRTIO, the master queries the satellite for buffer space. The satellite
uses as buffer space the space available in its fullest FIFO.
"""

View File

@ -0,0 +1,102 @@
from migen import *
from artiq.gateware.rtio.sed import layouts
from artiq.gateware.rtio.sed.lane_distributor import *
from artiq.gateware.rtio.sed.fifos import *
from artiq.gateware.rtio.sed.gates import *
from artiq.gateware.rtio.sed.output_driver import *
__all__ = ["SED"]
class SED(Module):
def __init__(self, channels, glbl_fine_ts_width, mode,
lane_count=8, fifo_depth=128, enable_spread=True,
quash_channels=[], report_buffer_space=False, interface=None):
if mode == "sync":
lane_dist_cdr = lambda x: x
fifos_cdr = lambda x: x
gates_cdr = lambda x: x
output_driver_cdr = lambda x: x
elif mode == "async":
lane_dist_cdr = ClockDomainsRenamer("rsys")
fifos_cdr = ClockDomainsRenamer({"write": "rsys", "read": "rio"})
gates_cdr = ClockDomainsRenamer("rio")
output_driver_cdr = ClockDomainsRenamer("rio")
else:
raise ValueError
seqn_width = layouts.seqn_width(lane_count, fifo_depth)
self.submodules.lane_dist = lane_dist_cdr(
LaneDistributor(lane_count, seqn_width,
layouts.fifo_payload(channels),
[channel.interface.o.delay for channel in channels],
glbl_fine_ts_width,
enable_spread=enable_spread,
quash_channels=quash_channels,
interface=interface))
self.submodules.fifos = fifos_cdr(
FIFOs(lane_count, fifo_depth,
layouts.fifo_payload(channels), mode, report_buffer_space))
self.submodules.gates = gates_cdr(
Gates(lane_count, seqn_width,
layouts.fifo_payload(channels),
layouts.output_network_payload(channels, glbl_fine_ts_width)))
self.submodules.output_driver = output_driver_cdr(
OutputDriver(channels, glbl_fine_ts_width, lane_count, seqn_width))
for o, i in zip(self.lane_dist.output, self.fifos.input):
self.comb += o.connect(i)
for o, i in zip(self.fifos.output, self.gates.input):
self.comb += o.connect(i)
for o, i in zip(self.gates.output, self.output_driver.input):
self.comb += i.eq(o)
if report_buffer_space:
self.comb += self.cri.o_buffer_space.eq(self.fifos.buffer_space)
@property
def cri(self):
return self.lane_dist.cri
# in CRI clock domain
@property
def minimum_coarse_timestamp(self):
return self.lane_dist.minimum_coarse_timestamp
# in I/O clock domain
@property
def coarse_timestamp(self):
return self.gates.coarse_timestamp
# in CRI clock domain
@property
def sequence_error(self):
return self.lane_dist.sequence_error
# in CRI clock domain
@property
def sequence_error_channel(self):
return self.lane_dist.sequence_error_channel
# in I/O clock domain
@property
def collision(self):
return self.output_driver.collision
# in I/O clock domain
@property
def collision_channel(self):
return self.output_driver.collision_channel
# in I/O clock domain
@property
def busy(self):
return self.output_driver.busy
# in I/O clock domain
@property
def busy_channel(self):
return self.output_driver.busy_channel

View File

@ -0,0 +1,84 @@
from operator import or_
from functools import reduce
from migen import *
from migen.genlib.fifo import *
from artiq.gateware.rtio.sed import layouts
__all__ = ["FIFOs"]
class FIFOs(Module):
def __init__(self, lane_count, fifo_depth, layout_payload, mode, report_buffer_space=False):
seqn_width = layouts.seqn_width(lane_count, fifo_depth)
self.input = [Record(layouts.fifo_ingress(seqn_width, layout_payload))
for _ in range(lane_count)]
self.output = [Record(layouts.fifo_egress(seqn_width, layout_payload))
for _ in range(lane_count)]
if report_buffer_space:
self.buffer_space = Signal(max=fifo_depth+1)
# # #
if mode == "sync":
fifo_cls = SyncFIFOBuffered
elif mode == "async":
fifo_cls = AsyncFIFO
else:
raise ValueError
fifos = []
for input, output in zip(self.input, self.output):
fifo = fifo_cls(layout_len(layout_payload), fifo_depth)
self.submodules += fifo
fifos.append(fifo)
self.comb += [
fifo.din.eq(input.payload.raw_bits()),
fifo.we.eq(input.we),
input.writable.eq(fifo.writable),
output.payload.raw_bits().eq(fifo.dout),
output.readable.eq(fifo.readable),
fifo.re.eq(output.re)
]
if report_buffer_space:
if mode != "sync":
raise NotImplementedError
def compute_max(elts):
l = len(elts)
if l == 1:
return elts[0], 0
else:
maximum1, latency1 = compute_max(elts[:l//2])
maximum2, latency2 = compute_max(elts[l//2:])
maximum = Signal(max(len(maximum1), len(maximum2)))
self.sync += [
If(maximum1 > maximum2,
maximum.eq(maximum1)
).Else(
maximum.eq(maximum2)
)
]
latency = max(latency1, latency2) + 1
return maximum, latency
max_level, latency = compute_max([fifo.level for fifo in fifos])
max_level_valid = Signal()
max_level_valid_counter = Signal(max=latency)
self.sync += [
If(reduce(or_, [fifo.we for fifo in fifos]),
max_level_valid.eq(0),
max_level_valid_counter.eq(latency - 1)
).Elif(max_level_valid_counter == 0,
max_level_valid.eq(1)
).Else(
max_level_valid_counter.eq(max_level_valid_counter - 1)
)
]
self.comb += If(max_level_valid, self.buffer_space.eq(fifo_depth - max_level))

View File

@ -0,0 +1,38 @@
from migen import *
from artiq.gateware.rtio.sed import layouts
__all__ = ["Gates"]
class Gates(Module):
def __init__(self, lane_count, seqn_width, layout_fifo_payload, layout_output_network_payload):
self.input = [Record(layouts.fifo_egress(seqn_width, layout_fifo_payload))
for _ in range(lane_count)]
self.output = [Record(layouts.output_network_node(seqn_width, layout_output_network_payload))
for _ in range(lane_count)]
if hasattr(self.output[0].payload, "fine_ts"):
glbl_fine_ts_width = len(self.output[0].payload.fine_ts)
else:
glbl_fine_ts_width = 0
self.coarse_timestamp = Signal(64-glbl_fine_ts_width)
# # #
for input, output in zip(self.input, self.output):
for field, _ in output.payload.layout:
if field == "fine_ts":
self.sync += output.payload.fine_ts.eq(input.payload.timestamp[:glbl_fine_ts_width])
else:
self.sync += getattr(output.payload, field).eq(getattr(input.payload, field))
self.sync += output.seqn.eq(input.seqn)
self.comb += [
output.replace_occured.eq(0),
output.nondata_replace_occured.eq(0)
]
self.comb += input.re.eq(input.payload.timestamp[glbl_fine_ts_width:] == self.coarse_timestamp)
self.sync += output.valid.eq(input.re & input.readable)

View File

@ -0,0 +1,158 @@
from migen import *
from artiq.gateware.rtio import cri
from artiq.gateware.rtio.sed import layouts
__all__ = ["LaneDistributor"]
# CRI write happens in 3 cycles:
# 1. set timestamp and channel
# 2. set other payload elements and issue write command
# 3. check status
class LaneDistributor(Module):
def __init__(self, lane_count, seqn_width, layout_payload,
compensation, glbl_fine_ts_width,
enable_spread=True, quash_channels=[], interface=None):
if lane_count & (lane_count - 1):
raise NotImplementedError("lane count must be a power of 2")
if interface is None:
interface = cri.Interface()
self.cri = interface
self.sequence_error = Signal()
self.sequence_error_channel = Signal(16)
self.minimum_coarse_timestamp = Signal(64-glbl_fine_ts_width)
self.output = [Record(layouts.fifo_ingress(seqn_width, layout_payload))
for _ in range(lane_count)]
# # #
o_status_wait = Signal()
o_status_underflow = Signal()
self.comb += self.cri.o_status.eq(Cat(o_status_wait, o_status_underflow))
# internal state
current_lane = Signal(max=lane_count)
last_coarse_timestamp = Signal(64-glbl_fine_ts_width)
last_lane_coarse_timestamps = Array(Signal(64-glbl_fine_ts_width)
for _ in range(lane_count))
seqn = Signal(seqn_width)
# distribute data to lanes
for lio in self.output:
self.comb += [
lio.seqn.eq(seqn),
lio.payload.channel.eq(self.cri.chan_sel[:16]),
lio.payload.timestamp.eq(self.cri.timestamp),
]
if hasattr(lio.payload, "address"):
self.comb += lio.payload.address.eq(self.cri.o_address)
if hasattr(lio.payload, "data"):
self.comb += lio.payload.data.eq(self.cri.o_data)
# when timestamp and channel arrive in cycle #1, prepare computations
us_timestamp_width = 64 - glbl_fine_ts_width
coarse_timestamp = Signal(us_timestamp_width)
self.comb += coarse_timestamp.eq(self.cri.timestamp[glbl_fine_ts_width:])
min_minus_timestamp = Signal((us_timestamp_width + 1, True))
laneAmin_minus_timestamp = Signal((us_timestamp_width + 1, True))
laneBmin_minus_timestamp = Signal((us_timestamp_width + 1, True))
last_minus_timestamp = Signal((us_timestamp_width + 1, True))
current_lane_plus_one = Signal(max=lane_count)
self.comb += current_lane_plus_one.eq(current_lane + 1)
self.sync += [
min_minus_timestamp.eq(self.minimum_coarse_timestamp - coarse_timestamp),
laneAmin_minus_timestamp.eq(last_lane_coarse_timestamps[current_lane] - coarse_timestamp),
laneBmin_minus_timestamp.eq(last_lane_coarse_timestamps[current_lane_plus_one] - coarse_timestamp),
last_minus_timestamp.eq(last_coarse_timestamp - coarse_timestamp)
]
quash = Signal()
self.sync += quash.eq(0)
for channel in quash_channels:
self.sync += If(self.cri.chan_sel[:16] == channel, quash.eq(1))
latency_compensation = Memory(14, len(compensation), init=compensation)
latency_compensation_port = latency_compensation.get_port()
self.specials += latency_compensation, latency_compensation_port
self.comb += latency_compensation_port.adr.eq(self.cri.chan_sel[:16])
# cycle #2, write
compensation = Signal((14, True))
self.comb += compensation.eq(latency_compensation_port.dat_r)
timestamp_above_min = Signal()
timestamp_above_laneA_min = Signal()
timestamp_above_laneB_min = Signal()
timestamp_above_lane_min = Signal()
force_laneB = Signal()
use_laneB = Signal()
use_lanen = Signal(max=lane_count)
do_write = Signal()
do_underflow = Signal()
do_sequence_error = Signal()
self.comb += [
timestamp_above_min.eq(min_minus_timestamp - compensation < 0),
timestamp_above_laneA_min.eq(laneAmin_minus_timestamp - compensation < 0),
timestamp_above_laneB_min.eq(laneBmin_minus_timestamp - compensation < 0),
If(force_laneB | (last_minus_timestamp - compensation >= 0),
use_lanen.eq(current_lane + 1),
use_laneB.eq(1)
).Else(
use_lanen.eq(current_lane),
use_laneB.eq(0)
),
timestamp_above_lane_min.eq(Mux(use_laneB, timestamp_above_laneB_min, timestamp_above_laneA_min)),
If(~quash,
do_write.eq((self.cri.cmd == cri.commands["write"]) & timestamp_above_min & timestamp_above_lane_min),
do_underflow.eq((self.cri.cmd == cri.commands["write"]) & ~timestamp_above_min),
do_sequence_error.eq((self.cri.cmd == cri.commands["write"]) & timestamp_above_min & ~timestamp_above_lane_min),
),
Array(lio.we for lio in self.output)[use_lanen].eq(do_write)
]
compensated_timestamp = Signal(64)
self.comb += compensated_timestamp.eq(self.cri.timestamp + (compensation << glbl_fine_ts_width))
self.sync += [
If(do_write,
If(use_laneB, current_lane.eq(current_lane + 1)),
last_coarse_timestamp.eq(compensated_timestamp[glbl_fine_ts_width:]),
last_lane_coarse_timestamps[use_lanen].eq(compensated_timestamp[glbl_fine_ts_width:]),
seqn.eq(seqn + 1),
)
]
for lio in self.output:
self.comb += lio.payload.timestamp.eq(compensated_timestamp)
# cycle #3, read status
current_lane_writable = Signal()
self.comb += [
current_lane_writable.eq(Array(lio.writable for lio in self.output)[current_lane]),
o_status_wait.eq(~current_lane_writable)
]
self.sync += [
If(self.cri.cmd == cri.commands["write"],
o_status_underflow.eq(0)
),
If(do_underflow,
o_status_underflow.eq(1)
),
self.sequence_error.eq(do_sequence_error),
self.sequence_error_channel.eq(self.cri.chan_sel[:16])
]
# current lane has been full, spread events by switching to the next.
if enable_spread:
current_lane_writable_r = Signal(reset=1)
self.sync += [
current_lane_writable_r.eq(current_lane_writable),
If(~current_lane_writable_r & current_lane_writable,
force_laneB.eq(1)
),
If(do_write,
force_laneB.eq(0)
)
]

View File

@ -0,0 +1,77 @@
from migen import *
from artiq.gateware.rtio import rtlink
def fifo_payload(channels):
address_width = max(rtlink.get_address_width(channel.interface.o)
for channel in channels)
data_width = max(rtlink.get_data_width(channel.interface.o)
for channel in channels)
layout = [
("channel", bits_for(len(channels)-1)),
("timestamp", 64)
]
if address_width:
layout.append(("address", address_width))
if data_width:
layout.append(("data", data_width))
return layout
def seqn_width(lane_count, fifo_depth):
# There must be a unique sequence number for every possible event in every FIFO.
# Plus 2 bits to detect and handle wraparounds.
return bits_for(lane_count*fifo_depth-1) + 2
def fifo_ingress(seqn_width, layout_payload):
return [
("we", 1, DIR_M_TO_S),
("writable", 1, DIR_S_TO_M),
("seqn", seqn_width, DIR_M_TO_S),
("payload", [(a, b, DIR_M_TO_S) for a, b in layout_payload])
]
def fifo_egress(seqn_width, layout_payload):
return [
("re", 1, DIR_S_TO_M),
("readable", 1, DIR_M_TO_S),
("seqn", seqn_width, DIR_M_TO_S),
("payload", [(a, b, DIR_M_TO_S) for a, b in layout_payload])
]
# We use glbl_fine_ts_width in the output network so that collisions due
# to insufficiently increasing timestamps are always reliably detected.
# We can still have undetected collisions on the address by making it wrap
# around, but those are more rare and easier to debug, and addresses are
# not normally exposed directly to the ARTIQ user.
def output_network_payload(channels, glbl_fine_ts_width):
address_width = max(rtlink.get_address_width(channel.interface.o)
for channel in channels)
data_width = max(rtlink.get_data_width(channel.interface.o)
for channel in channels)
layout = [("channel", bits_for(len(channels)-1))]
if glbl_fine_ts_width:
layout.append(("fine_ts", glbl_fine_ts_width))
if address_width:
layout.append(("address", address_width))
if data_width:
layout.append(("data", data_width))
return layout
def output_network_node(seqn_width, layout_payload):
return [
("valid", 1),
("seqn", seqn_width),
("replace_occured", 1),
("nondata_replace_occured", 1),
("payload", layout_payload)
]

View File

@ -0,0 +1,108 @@
from functools import reduce
from operator import or_
from migen import *
from artiq.gateware.rtio.sed import layouts
from artiq.gateware.rtio.sed.output_network import OutputNetwork
__all__ = ["OutputDriver"]
class OutputDriver(Module):
def __init__(self, channels, glbl_fine_ts_width, lane_count, seqn_width):
self.collision = Signal()
self.collision_channel = Signal(max=len(channels))
self.busy = Signal()
self.busy_channel = Signal(max=len(channels))
# output network
layout_on_payload = layouts.output_network_payload(channels, glbl_fine_ts_width)
output_network = OutputNetwork(lane_count, seqn_width, layout_on_payload)
self.submodules += output_network
self.input = output_network.input
# detect collisions (adds one pipeline stage)
layout_lane_data = [
("valid", 1),
("collision", 1),
("payload", layout_on_payload)
]
lane_datas = [Record(layout_lane_data) for _ in range(lane_count)]
en_replaces = [channel.interface.o.enable_replace for channel in channels]
for lane_data, on_output in zip(lane_datas, output_network.output):
replace_occured_r = Signal()
nondata_replace_occured_r = Signal()
self.sync += [
lane_data.valid.eq(on_output.valid),
lane_data.payload.eq(on_output.payload),
replace_occured_r.eq(on_output.replace_occured),
nondata_replace_occured_r.eq(on_output.nondata_replace_occured)
]
en_replaces_rom = Memory(1, len(en_replaces), init=en_replaces)
en_replaces_rom_port = en_replaces_rom.get_port()
self.specials += en_replaces_rom, en_replaces_rom_port
self.comb += [
en_replaces_rom_port.adr.eq(on_output.payload.channel),
lane_data.collision.eq(replace_occured_r & (~en_replaces_rom_port.dat_r | nondata_replace_occured_r))
]
self.sync += [
self.collision.eq(0),
self.collision_channel.eq(0)
]
for lane_data in lane_datas:
self.sync += [
If(lane_data.valid & lane_data.collision,
self.collision.eq(1),
self.collision_channel.eq(lane_data.payload.channel)
)
]
# demultiplex channels (adds one pipeline stage)
for n, channel in enumerate(channels):
oif = channel.interface.o
onehot_stb = []
onehot_fine_ts = []
onehot_address = []
onehot_data = []
for lane_data in lane_datas:
selected = Signal()
self.comb += selected.eq(lane_data.valid & ~lane_data.collision & (lane_data.payload.channel == n))
onehot_stb.append(selected)
if hasattr(lane_data.payload, "fine_ts") and hasattr(oif, "fine_ts"):
ts_shift = len(lane_data.payload.fine_ts) - len(oif.fine_ts)
onehot_fine_ts.append(Mux(selected, lane_data.payload.fine_ts[ts_shift:], 0))
if hasattr(lane_data.payload, "address"):
onehot_address.append(Mux(selected, lane_data.payload.address, 0))
if hasattr(lane_data.payload, "data"):
onehot_data.append(Mux(selected, lane_data.payload.data, 0))
self.sync += oif.stb.eq(reduce(or_, onehot_stb))
if hasattr(oif, "fine_ts"):
self.sync += oif.fine_ts.eq(reduce(or_, onehot_fine_ts))
if hasattr(oif, "address"):
self.sync += oif.address.eq(reduce(or_, onehot_address))
if hasattr(oif, "data"):
self.sync += oif.data.eq(reduce(or_, onehot_data))
# detect busy errors, at lane level to reduce muxing
self.sync += [
self.busy.eq(0),
self.busy_channel.eq(0)
]
for lane_data in lane_datas:
stb_r = Signal()
channel_r = Signal(max=len(channels))
self.sync += [
stb_r.eq(lane_data.valid & ~lane_data.collision),
channel_r.eq(lane_data.payload.channel),
If(stb_r & Array(channel.interface.o.busy for channel in channels)[channel_r],
self.busy.eq(1),
self.busy_channel.eq(channel_r)
)
]

View File

@ -0,0 +1,101 @@
from migen import *
from artiq.gateware.rtio.sed import layouts
__all__ = ["latency", "OutputNetwork"]
# Based on: https://github.com/Bekbolatov/SortingNetworks/blob/master/src/main/js/gr.js
def boms_get_partner(n, l, p):
if p == 1:
return n ^ (1 << (l - 1))
scale = 1 << (l - p)
box = 1 << p
sn = n//scale - n//scale//box*box
if sn == 0 or sn == (box - 1):
return n
if (sn % 2) == 0:
return n - scale
return n + scale
def boms_steps_pairs(lane_count):
d = log2_int(lane_count)
steps = []
for l in range(1, d+1):
for p in range(1, l+1):
pairs = []
for n in range(2**d):
partner = boms_get_partner(n, l, p)
if partner != n:
if partner > n:
pair = (n, partner)
else:
pair = (partner, n)
if pair not in pairs:
pairs.append(pair)
steps.append(pairs)
return steps
def latency(lane_count):
d = log2_int(lane_count)
return sum(l for l in range(1, d+1))
def cmp_wrap(a, b):
return Mux(a[-2:] == ~b[-2:], a[0], a[:-2] < b[:-2])
class OutputNetwork(Module):
def __init__(self, lane_count, seqn_width, layout_payload):
self.input = [Record(layouts.output_network_node(seqn_width, layout_payload))
for _ in range(lane_count)]
self.output = None
step_input = self.input
for step in boms_steps_pairs(lane_count):
step_output = [Record(layouts.output_network_node(seqn_width, layout_payload))
for _ in range(lane_count)]
for node1, node2 in step:
nondata_difference = Signal()
for field, _ in layout_payload:
if field != "data":
f1 = getattr(step_input[node1].payload, field)
f2 = getattr(step_input[node2].payload, field)
self.comb += If(f1 != f2, nondata_difference.eq(1))
k1 = Cat(step_input[node1].payload.channel, ~step_input[node1].valid)
k2 = Cat(step_input[node2].payload.channel, ~step_input[node2].valid)
self.sync += [
If(k1 == k2,
If(cmp_wrap(step_input[node1].seqn, step_input[node2].seqn),
step_output[node1].eq(step_input[node2]),
step_output[node2].eq(step_input[node1])
).Else(
step_output[node1].eq(step_input[node1]),
step_output[node2].eq(step_input[node2])
),
step_output[node1].replace_occured.eq(1),
step_output[node1].nondata_replace_occured.eq(nondata_difference),
step_output[node2].valid.eq(0),
).Elif(k1 < k2,
step_output[node1].eq(step_input[node1]),
step_output[node2].eq(step_input[node2])
).Else(
step_output[node1].eq(step_input[node2]),
step_output[node2].eq(step_input[node1])
)
]
unchanged = list(range(lane_count))
for node1, node2 in step:
unchanged.remove(node1)
unchanged.remove(node2)
for node in unchanged:
self.sync += step_output[node].eq(step_input[node])
self.output = step_output
step_input = step_output

View File

@ -319,18 +319,18 @@ class NIST_CLOCK(_NIST_Ions):
phy = spi.SPIMaster(ams101_dac)
self.submodules += phy
rtio_channels.append(rtio.Channel.from_phy(
phy, ofifo_depth=4, ififo_depth=4))
phy, ififo_depth=4))
for i in range(3):
phy = spi.SPIMaster(self.platform.request("spi", i))
self.submodules += phy
rtio_channels.append(rtio.Channel.from_phy(
phy, ofifo_depth=128, ififo_depth=128))
phy, ififo_depth=128))
phy = spi.SPIMaster(platform.request("sdcard_spi_33"))
self.submodules += phy
rtio_channels.append(rtio.Channel.from_phy(
phy, ofifo_depth=4, ififo_depth=4))
phy, ififo_depth=4))
fmcdio_dirctl = self.platform.request("fmcdio_dirctl")
for s in fmcdio_dirctl.clk, fmcdio_dirctl.ser, fmcdio_dirctl.latch:
@ -365,9 +365,7 @@ class NIST_CLOCK(_NIST_Ions):
phy = dds.AD9914(platform.request("dds"), 11, onehot=True)
self.submodules += phy
rtio_channels.append(rtio.Channel.from_phy(phy,
ofifo_depth=512,
ififo_depth=4))
rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=4))
self.config["HAS_RTIO_LOG"] = None
self.config["RTIO_LOG_CHANNEL"] = len(rtio_channels)
@ -425,21 +423,19 @@ class NIST_QC2(_NIST_Ions):
phy = spi.SPIMaster(ams101_dac)
self.submodules += phy
rtio_channels.append(rtio.Channel.from_phy(
phy, ofifo_depth=4, ififo_depth=4))
phy, ififo_depth=4))
for i in range(4):
phy = spi.SPIMaster(self.platform.request("spi", i))
self.submodules += phy
rtio_channels.append(rtio.Channel.from_phy(
phy, ofifo_depth=128, ififo_depth=128))
phy, ififo_depth=128))
for backplane_offset in range(2):
phy = dds.AD9914(
platform.request("dds", backplane_offset), 12, onehot=True)
self.submodules += phy
rtio_channels.append(rtio.Channel.from_phy(phy,
ofifo_depth=512,
ififo_depth=4))
rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=4))
self.config["HAS_RTIO_LOG"] = None
self.config["RTIO_LOG_CHANNEL"] = len(rtio_channels)

View File

@ -101,12 +101,12 @@ class SMA_SPI(_NIST_Ions):
phy = spi.SPIMaster(ams101_dac)
self.submodules += phy
rtio_channels.append(rtio.Channel.from_phy(
phy, ofifo_depth=4, ififo_depth=4))
phy, ififo_depth=4))
phy = spi.SPIMaster(self.platform.request("sma_spi"))
self.submodules += phy
rtio_channels.append(rtio.Channel.from_phy(
phy, ofifo_depth=128, ififo_depth=128))
phy, ififo_depth=128))
self.config["HAS_RTIO_LOG"] = None
self.config["RTIO_LOG_CHANNEL"] = len(rtio_channels)

View File

@ -103,7 +103,7 @@ class Master(MiniSoC, AMPSoC):
self.submodules.rtio_moninj = rtio.MonInj(rtio_channels)
self.csr_devices.append("rtio_moninj")
self.submodules.rtio_core = rtio.Core(rtio_channels, 3)
self.submodules.rtio_core = rtio.Core(rtio_channels, glbl_fine_ts_width=3)
self.csr_devices.append("rtio_core")
self.submodules.rtio = rtio.KernelInitiator()

View File

@ -52,7 +52,8 @@ class DUT(Module):
self.ttl1 = Signal()
self.transceivers = DummyTransceiverPair(nwords)
self.submodules.master = DRTIOMaster(self.transceivers.alice)
self.submodules.master = DRTIOMaster(self.transceivers.alice,
fine_ts_width=0)
self.submodules.master_ki = rtio.KernelInitiator(self.master.cri)
rx_synchronizer = DummyRXSynchronizer()
@ -60,132 +61,164 @@ class DUT(Module):
self.submodules.phy1 = ttl_simple.Output(self.ttl1)
self.submodules.phy2 = SimpleIOPHY(512, 32) # test wide output data
rtio_channels = [
rtio.Channel.from_phy(self.phy0, ofifo_depth=4),
rtio.Channel.from_phy(self.phy1, ofifo_depth=4),
rtio.Channel.from_phy(self.phy2, ofifo_depth=4),
rtio.Channel.from_phy(self.phy0),
rtio.Channel.from_phy(self.phy1),
rtio.Channel.from_phy(self.phy2),
]
self.submodules.satellite = DRTIOSatellite(
self.transceivers.bob, rtio_channels, rx_synchronizer)
self.transceivers.bob, rtio_channels, rx_synchronizer,
lane_count=4, fifo_depth=8, fine_ts_width=0)
class OutputsTestbench:
def __init__(self):
self.dut = DUT(2)
self.now = 0
def init(self):
yield from self.dut.master.rt_controller.csrs.underflow_margin.write(100)
while not (yield from self.dut.master.link_layer.link_status.read()):
yield
yield from self.get_buffer_space()
def get_buffer_space(self):
csrs = self.dut.master.rt_controller.csrs
yield from csrs.o_get_buffer_space.write(1)
yield
while (yield from csrs.o_wait.read()):
yield
r = (yield from csrs.o_dbg_buffer_space.read())
return r
def delay(self, dt):
self.now += dt
def sync(self):
t = self.now + 15
while (yield self.dut.master.cri.counter) < t:
yield
def write(self, channel, data):
kcsrs = self.dut.master_ki
yield from kcsrs.chan_sel.write(channel)
yield from kcsrs.timestamp.write(self.now)
yield from kcsrs.o_data.write(data)
yield from kcsrs.o_we.write(1)
yield
status = 1
wlen = 0
while status:
status = yield from kcsrs.o_status.read()
if status & 2:
raise RTIOUnderflow
yield
wlen += 1
return wlen
@passive
def check_ttls(self, ttl_changes):
cycle = 0
old_ttls = [0, 0]
while True:
ttls = [(yield self.dut.ttl0), (yield self.dut.ttl1)]
for n, (old_ttl, ttl) in enumerate(zip(old_ttls, ttls)):
if ttl != old_ttl:
ttl_changes.append((cycle, n))
old_ttls = ttls
yield
cycle += 1
class TestFullStack(unittest.TestCase):
clocks = {"sys": 8, "rtio": 5, "rtio_rx": 5,
"rio": 5, "rio_phy": 5,
"sys_with_rst": 8, "rtio_with_rst": 5}
def test_outputs(self):
dut = DUT(2)
kcsrs = dut.master_ki
csrs = dut.master.rt_controller.csrs
mgr = dut.master.rt_manager
saterr = dut.satellite.rt_errors
def test_pulses(self):
tb = OutputsTestbench()
ttl_changes = []
correct_ttl_changes = [
# from test_pulses
(203, 0),
(208, 0),
(208, 1),
(214, 1),
# from test_fifo_space
(414, 0),
(454, 0),
(494, 0),
(534, 0),
(574, 0),
(614, 0)
(213, 0),
(213, 1),
(219, 1),
]
now = 0
def delay(dt):
nonlocal now
now += dt
def test():
yield from tb.init()
tb.delay(200)
yield from tb.write(0, 1)
tb.delay(5)
yield from tb.write(0, 0)
yield from tb.write(1, 1)
tb.delay(6)
yield from tb.write(1, 0)
yield from tb.sync()
def get_fifo_space(channel):
yield from csrs.chan_sel_override_en.write(1)
yield from csrs.chan_sel_override.write(channel)
yield from csrs.o_get_fifo_space.write(1)
yield
while (yield from csrs.o_wait.read()):
yield
r = (yield from csrs.o_dbg_fifo_space.read())
yield from csrs.chan_sel_override_en.write(0)
return r
run_simulation(tb.dut,
{"sys": test(), "rtio": tb.check_ttls(ttl_changes)}, self.clocks)
self.assertEqual(ttl_changes, correct_ttl_changes)
def write(channel, data):
yield from kcsrs.chan_sel.write(channel)
yield from kcsrs.timestamp.write(now)
yield from kcsrs.o_data.write(data)
yield from kcsrs.o_we.write(1)
yield
status = 1
wlen = 0
while status:
status = yield from kcsrs.o_status.read()
if status & 2:
raise RTIOUnderflow
if status & 4:
raise RTIOSequenceError
yield
wlen += 1
return wlen
def test_underflow(self):
tb = OutputsTestbench()
def test_init():
yield from get_fifo_space(0)
yield from get_fifo_space(1)
def test_underflow():
def test():
yield from tb.init()
with self.assertRaises(RTIOUnderflow):
yield from write(0, 0)
yield from tb.write(0, 0)
def test_pulses():
delay(200*8)
yield from write(0, 1)
delay(5*8)
yield from write(0, 1)
yield from write(0, 0) # replace
yield from write(1, 1)
delay(6*8)
yield from write(1, 0)
run_simulation(tb.dut, {"sys": test()}, self.clocks)
def test_sequence_error():
delay(-200*8)
with self.assertRaises(RTIOSequenceError):
yield from write(0, 1)
delay(200*8)
def test_large_data(self):
tb = OutputsTestbench()
def test_large_data():
def test():
yield from tb.init()
correct_large_data = random.Random(0).randrange(2**512-1)
self.assertNotEqual((yield dut.phy2.received_data), correct_large_data)
delay(10*8)
yield from write(2, correct_large_data)
for i in range(45):
yield
self.assertEqual((yield dut.phy2.received_data), correct_large_data)
self.assertNotEqual((yield tb.dut.phy2.received_data), correct_large_data)
tb.delay(200)
yield from tb.write(2, correct_large_data)
yield from tb.sync()
self.assertEqual((yield tb.dut.phy2.received_data), correct_large_data)
def test_fifo_space():
delay(200*8)
run_simulation(tb.dut, {"sys": test()}, self.clocks)
def test_buffer_space(self):
tb = OutputsTestbench()
ttl_changes = []
correct_ttl_changes = [(258 + 40*i, 0) for i in range(10)]
def test():
yield from tb.init()
tb.delay(250)
max_wlen = 0
for _ in range(3):
wlen = yield from write(0, 1)
for i in range(10):
wlen = yield from tb.write(0, (i + 1) % 2)
max_wlen = max(max_wlen, wlen)
delay(40*8)
wlen = yield from write(0, 0)
max_wlen = max(max_wlen, wlen)
delay(40*8)
# check that some writes caused FIFO space requests
tb.delay(40)
# check that some writes caused buffer space requests
self.assertGreater(max_wlen, 5)
yield from tb.sync()
def test_tsc_error():
run_simulation(tb.dut,
{"sys": test(), "rtio": tb.check_ttls(ttl_changes)}, self.clocks)
self.assertEqual(ttl_changes, correct_ttl_changes)
def test_tsc_error(self):
tb = OutputsTestbench()
def test():
saterr = tb.dut.satellite.rt_errors
csrs = tb.dut.master.rt_controller.csrs
yield from tb.init()
errors = yield from saterr.protocol_error.read()
self.assertEqual(errors, 0)
yield from csrs.tsc_correction.write(100000000)
yield from csrs.set_time.write(1)
for i in range(15):
yield
delay(10000*8)
yield from write(0, 1)
tb.delay(10000)
yield from tb.write(0, 1)
for i in range(12):
yield
errors = yield from saterr.protocol_error.read()
@ -195,39 +228,7 @@ class TestFullStack(unittest.TestCase):
errors = yield from saterr.protocol_error.read()
self.assertEqual(errors, 0)
def wait_ttl_events():
while len(ttl_changes) < len(correct_ttl_changes):
yield
def test():
while not (yield from dut.master.link_layer.link_status.read()):
yield
yield from test_init()
yield from test_underflow()
yield from test_pulses()
yield from test_sequence_error()
yield from test_fifo_space()
yield from test_large_data()
yield from test_tsc_error()
yield from wait_ttl_events()
@passive
def check_ttls():
cycle = 0
old_ttls = [0, 0]
while True:
ttls = [(yield dut.ttl0), (yield dut.ttl1)]
for n, (old_ttl, ttl) in enumerate(zip(old_ttls, ttls)):
if ttl != old_ttl:
ttl_changes.append((cycle, n))
old_ttls = ttls
yield
cycle += 1
run_simulation(dut,
{"sys": test(), "rtio": check_ttls()}, self.clocks)
self.assertEqual(ttl_changes, correct_ttl_changes)
run_simulation(tb.dut, {"sys": test()}, self.clocks)
def test_inputs(self):
dut = DUT(2)
@ -250,8 +251,7 @@ class TestFullStack(unittest.TestCase):
(yield from kcsrs.i_timestamp.read()))
def test():
# wait for link layer ready
for i in range(5):
while not (yield from dut.master.link_layer.link_status.read()):
yield
i1 = yield from get_input(10)
@ -269,7 +269,7 @@ class TestFullStack(unittest.TestCase):
yield dut.phy2.rtlink.i.stb.eq(0)
run_simulation(dut,
{"sys": test(), "rtio": generate_input()}, self.clocks, vcd_name="foo.vcd")
{"sys": test(), "rtio": generate_input()}, self.clocks)
def test_echo(self):
dut = DUT(2)

View File

@ -1,10 +1,14 @@
import unittest
import random
import itertools
from migen import *
from misoc.interconnect import wishbone
from artiq.coredevice.exceptions import RTIOUnderflow
from artiq.gateware import rtio
from artiq.gateware.rtio import dma, cri
from artiq.gateware.rtio.phy import ttl_simple
def encode_n(n, min_length, max_length):
@ -47,6 +51,16 @@ def encode_sequence(writes, ws):
return pack(sequence, ws)
def do_dma(dut, address):
yield from dut.dma.base_address.write(address)
yield from dut.enable.write(1)
yield
while ((yield from dut.enable.read())):
yield
if (yield from dut.cri_master.underflow.read()):
raise RTIOUnderflow
test_writes1 = [
(0x01, 0x23, 0x12, 0x33),
(0x901, 0x902, 0x911, 0xeeeeeeeeeeeeeefffffffffffffffffffffffffffffff28888177772736646717738388488),
@ -83,21 +97,44 @@ class TB(Module):
self.submodules.dut = dma.DMA(bus)
test_writes_full_stack = [
(0, 32, 0, 1),
(1, 40, 0, 1),
(0, 48, 0, 0),
(1, 50, 0, 0),
]
class FullStackTB(Module):
def __init__(self, ws):
self.ttl0 = Signal()
self.ttl1 = Signal()
self.submodules.phy0 = ttl_simple.Output(self.ttl0)
self.submodules.phy1 = ttl_simple.Output(self.ttl1)
rtio_channels = [
rtio.Channel.from_phy(self.phy0),
rtio.Channel.from_phy(self.phy1)
]
sequence = encode_sequence(test_writes_full_stack, ws)
bus = wishbone.Interface(ws*8)
self.submodules.memory = wishbone.SRAM(
256, init=sequence, bus=bus)
self.submodules.dut = dma.DMA(bus)
self.submodules.rtio = rtio.Core(rtio_channels)
self.comb += self.dut.cri.connect(self.rtio.cri)
class TestDMA(unittest.TestCase):
def test_dma_noerror(self):
ws = 64
tb = TB(ws)
def do_dma(address):
yield from tb.dut.dma.base_address.write(address)
yield from tb.dut.enable.write(1)
yield
while ((yield from tb.dut.enable.read())):
yield
tb = TB(64)
def do_writes():
yield from do_dma(0)
yield from do_dma(512)
yield from do_dma(tb.dut, 0)
yield from do_dma(tb.dut, 512)
received = []
@passive
@ -124,3 +161,30 @@ class TestDMA(unittest.TestCase):
run_simulation(tb, [do_writes(), rtio_sim()])
self.assertEqual(received, test_writes1 + test_writes2)
def test_full_stack(self):
tb = FullStackTB(64)
ttl_changes = []
@passive
def monitor():
old_ttl_states = [0, 0]
for time in itertools.count():
ttl_states = [
(yield tb.ttl0),
(yield tb.ttl1)
]
for i, (old, new) in enumerate(zip(old_ttl_states, ttl_states)):
if new != old:
ttl_changes.append((time, i))
old_ttl_states = ttl_states
yield
run_simulation(tb, {"sys": [
do_dma(tb.dut, 0), monitor(),
(None for _ in range(70)),
]}, {"sys": 8, "rsys": 8, "rtio": 8, "rio": 8, "rio_phy": 8})
correct_changes = [(timestamp + 11, channel)
for channel, timestamp, _, _ in test_writes_full_stack]
self.assertEqual(ttl_changes, correct_changes)

View File

@ -0,0 +1,90 @@
import unittest
from migen import *
from artiq.gateware import rtio
from artiq.gateware.rtio import rtlink
from artiq.gateware.rtio import cri
from artiq.gateware.rtio.input_collector import *
class OscInput(Module):
def __init__(self):
self.rtlink = rtlink.Interface(
rtlink.OInterface(1),
rtlink.IInterface(1))
self.overrides = []
self.probes = []
# # #
counter = Signal(2)
trigger = Signal()
self.sync += [
Cat(counter, trigger).eq(counter + 1),
self.rtlink.i.stb.eq(0),
If(trigger,
self.rtlink.i.stb.eq(1),
self.rtlink.i.data.eq(~self.rtlink.i.data)
)
]
class DUT(Module):
def __init__(self):
self.submodules.phy0 = OscInput()
self.submodules.phy1 = OscInput()
rtio_channels = [
rtio.Channel.from_phy(self.phy0, ififo_depth=4),
rtio.Channel.from_phy(self.phy1, ififo_depth=4)
]
self.submodules.input_collector = InputCollector(rtio_channels, 0, "sync")
self.sync += self.input_collector.coarse_timestamp.eq(self.input_collector.coarse_timestamp + 1)
self.comb += self.input_collector.cri.counter.eq(self.input_collector.coarse_timestamp)
@property
def cri(self):
return self.input_collector.cri
def simulate(wait_cycles, ts_timeouts):
result = []
dut = DUT()
def gen():
for _ in range(wait_cycles):
yield
for ts_timeout in ts_timeouts:
yield dut.cri.timestamp.eq(ts_timeout)
yield dut.cri.cmd.eq(cri.commands["read"])
yield
yield dut.cri.cmd.eq(cri.commands["nop"])
yield
while (yield dut.cri.i_status) & 4:
yield
status = yield dut.cri.i_status
if status & 2:
result.append("overflow")
elif status & 1:
result.append("timeout")
else:
i_timestamp = yield dut.cri.i_timestamp
i_data = yield dut.cri.i_data
result.append((i_timestamp, i_data))
run_simulation(dut, gen())
return result
class TestInput(unittest.TestCase):
def test_get_data(self):
result = simulate(0, [256]*8)
self.assertEqual(result, [(n*4+1, n % 2) for n in range(1, 9)])
def test_timeout(self):
result = simulate(0, [3, 16])
self.assertEqual(result, ["timeout", (5, 1)])
def test_overflow(self):
result = simulate(32, [256])
self.assertEqual(result, ["overflow"])

View File

@ -0,0 +1,153 @@
import unittest
from migen import *
from artiq.gateware.rtio import cri
from artiq.gateware.rtio.sed import lane_distributor
LANE_COUNT = 8
def simulate(input_events, compensation=None, wait=True):
layout = [("channel", 8), ("timestamp", 32)]
if compensation is None:
compensation = [0]*256
dut = lane_distributor.LaneDistributor(LANE_COUNT, 8, layout, compensation, 3)
output = []
access_results = []
def gen():
for channel, timestamp in input_events:
yield dut.cri.chan_sel.eq(channel)
yield dut.cri.timestamp.eq(timestamp)
yield
yield dut.cri.cmd.eq(cri.commands["write"])
yield
yield dut.cri.cmd.eq(cri.commands["nop"])
access_time = 0
yield
while (yield dut.cri.o_status) & 0x01:
yield
access_time += 1
status = (yield dut.cri.o_status)
access_status = "ok"
if status & 0x02:
access_status = "underflow"
if (yield dut.sequence_error):
access_status = "sequence_error"
access_results.append((access_status, access_time))
@passive
def monitor_lane(n, lio, wait_time):
yield lio.writable.eq(1)
while True:
while not (yield lio.we):
yield
seqn = (yield lio.seqn)
channel = (yield lio.payload.channel)
timestamp = (yield lio.payload.timestamp)
output.append((n, seqn, channel, timestamp))
yield lio.writable.eq(0)
for i in range(wait_time):
yield
yield lio.writable.eq(1)
yield
generators = [gen()]
for n, lio in enumerate(dut.output):
lio.writable.reset = 1
wait_time = 0
if wait:
if n == 6:
wait_time = 1
elif n == 7:
wait_time = 4
generators.append(monitor_lane(n, lio, wait_time))
run_simulation(dut, generators)
return output, access_results
class TestLaneDistributor(unittest.TestCase):
def test_regular(self):
N = 16
output, access_results = simulate([(42+n, (n+1)*8) for n in range(N)], wait=False)
self.assertEqual(output, [(0, n, 42+n, (n+1)*8) for n in range(N)])
self.assertEqual(access_results, [("ok", 0)]*N)
def test_wait_time(self):
output, access_results = simulate([(42+n, 8) for n in range(LANE_COUNT)])
self.assertEqual(output, [(n, n, 42+n, 8) for n in range(LANE_COUNT)])
expected_access_results = [("ok", 0)]*LANE_COUNT
expected_access_results[6] = ("ok", 1)
expected_access_results[7] = ("ok", 4)
self.assertEqual(access_results, expected_access_results)
def test_lane_switch(self):
N = 32
output, access_results = simulate([(42+n, n+8) for n in range(N)], wait=False)
self.assertEqual(output, [((n-n//8) % LANE_COUNT, n, 42+n, n+8) for n in range(N)])
self.assertEqual([ar[0] for ar in access_results], ["ok"]*N)
def test_sequence_error(self):
input_events = [(42+n, 8) for n in range(LANE_COUNT+1)]
input_events.append((42+LANE_COUNT+1, 16))
output, access_results = simulate(input_events)
self.assertEqual(len(output), len(input_events)-1) # event with sequence error must get discarded
self.assertEqual([ar[0] for ar in access_results[:LANE_COUNT]], ["ok"]*LANE_COUNT)
self.assertEqual(access_results[LANE_COUNT][0], "sequence_error")
def test_underflow(self):
N = 16
input_events = [(42+n, (n+1)*8) for n in range(N-2)]
input_events.append((0, 0)) # timestamp < 8 underflows
input_events.append((42+N-2, N*8))
output, access_results = simulate(input_events)
self.assertEqual(len(output), len(input_events)-1) # event with underflow must get discarded
self.assertEqual([ar[0] for ar in access_results[:N-2]], ["ok"]*(N-2))
self.assertEqual(access_results[N-2][0], "underflow")
self.assertEqual(output[N-2], (0, N-2, 42+N-2, N*8))
self.assertEqual(access_results[N-1][0], "ok")
def test_spread(self):
# get to lane 6
input_events = [(42+n, 8) for n in range(7)]
input_events.append((100, 16))
input_events.append((100, 32))
output, access_results = simulate(input_events)
self.assertEqual([o[0] for o in output], [x % LANE_COUNT for x in range(9)])
self.assertEqual([ar[0] for ar in access_results], ["ok"]*9)
def test_regular_lc(self):
N = 16
output, access_results = simulate([(n, 8) for n in range(N)],
compensation=range(N), wait=False)
self.assertEqual(output, [(0, n, n, (n+1)*8) for n in range(N)])
self.assertEqual(access_results, [("ok", 0)]*N)
def test_lane_switch_lc(self):
N = 32
compensation = [n//2 for n in range(N)]
output, access_results = simulate([(n, 8) for n in range(N)],
compensation=compensation, wait=False)
self.assertEqual(output, [((n-n//2) % LANE_COUNT, n, n, 8*(1+n//2)) for n in range(N)])
self.assertEqual([ar[0] for ar in access_results], ["ok"]*N)
def test_underflow_lc(self):
N = 16
compensation = [0]*N
input_events = [(n, (n+1)*8) for n in range(N)]
compensation[N-2] = -input_events[N-2][1]//8
output, access_results = simulate(input_events, compensation=compensation)
self.assertEqual(len(output), len(input_events)-1) # event with underflow must get discarded
self.assertEqual([ar[0] for ar in access_results[:N-2]], ["ok"]*(N-2))
self.assertEqual(access_results[N-2][0], "underflow")
self.assertEqual(output[N-2], (0, N-2, N-1, N*8))
self.assertEqual(access_results[N-1][0], "ok")

View File

@ -0,0 +1,125 @@
import unittest
from migen import *
from artiq.gateware import rtio
from artiq.gateware.rtio.sed import output_network, output_driver
from artiq.gateware.rtio.phy import ttl_simple
from artiq.gateware.rtio import rtlink
LANE_COUNT = 8
class BusyPHY(Module):
def __init__(self):
self.rtlink = rtlink.Interface(rtlink.OInterface(1))
self.comb += self.rtlink.o.busy.eq(1)
class DUT(Module):
def __init__(self):
self.ttl0 = Signal()
self.ttl1 = Signal()
self.ttl2 = Signal()
self.submodules.phy0 = ttl_simple.Output(self.ttl0)
self.submodules.phy1 = ttl_simple.Output(self.ttl1)
self.submodules.phy2 = ttl_simple.Output(self.ttl2)
self.phy2.rtlink.o.enable_replace = False
self.submodules.phy3 = BusyPHY()
rtio_channels = [
rtio.Channel.from_phy(self.phy0),
rtio.Channel.from_phy(self.phy1),
rtio.Channel.from_phy(self.phy2),
rtio.Channel.from_phy(self.phy3),
]
self.submodules.output_driver = output_driver.OutputDriver(
rtio_channels, 0, LANE_COUNT, 4*LANE_COUNT)
def simulate(input_events):
dut = DUT()
def gen():
for n, input_event in enumerate(input_events):
yield dut.output_driver.input[n].valid.eq(1)
yield dut.output_driver.input[n].seqn.eq(n)
for k, v in input_event.items():
yield getattr(dut.output_driver.input[n].payload, k).eq(v)
yield
for n in range(len(input_events)):
yield dut.output_driver.input[n].valid.eq(0)
for i in range(output_network.latency(LANE_COUNT) + 2):
yield
for i in range(3):
yield
output = ""
@passive
def monitor():
nonlocal output
ttls = [dut.ttl0, dut.ttl1, dut.ttl2]
prev_ttl_values = [0, 0, 0]
while True:
ttl_values = []
for ttl in ttls:
ttl_values.append((yield ttl))
for n, (old, new) in enumerate(zip(prev_ttl_values, ttl_values)):
if old != new:
output += "TTL{} {}->{}\n".format(n, old, new)
prev_ttl_values = ttl_values
if (yield dut.output_driver.collision):
output += "collision ch{}\n".format((yield dut.output_driver.collision_channel))
if (yield dut.output_driver.busy):
output += "busy ch{}\n".format((yield dut.output_driver.busy_channel))
yield
run_simulation(dut, {"sys": [gen(), monitor()]},
{"sys": 5, "rio": 5, "rio_phy": 5})
return output
class TestOutputNetwork(unittest.TestCase):
def test_one_ttl(self):
self.assertEqual(
simulate([{"data": 1}]),
"TTL0 0->1\n")
def test_simultaneous_ttl(self):
self.assertEqual(
simulate([{"channel": 0, "data": 1},
{"channel": 1, "data": 1},
{"channel": 2, "data": 1}]),
"TTL0 0->1\n"
"TTL1 0->1\n"
"TTL2 0->1\n")
def test_replace(self):
self.assertEqual(
simulate([{"data": 0},
{"data": 1},
{"data": 0}]),
"")
self.assertEqual(
simulate([{"data": 1},
{"data": 0},
{"data": 1}]),
"TTL0 0->1\n")
def test_collision(self):
self.assertEqual(
simulate([{"channel": 2},
{"channel": 2}]),
"collision ch2\n")
def test_busy(self):
self.assertEqual(
simulate([{"channel": 3}]),
"busy ch3\n")

View File

@ -0,0 +1,61 @@
import unittest
from migen import *
from artiq.gateware.rtio.sed import output_network
LANE_COUNT = 8
def simulate(input_events):
layout_payload = [
("channel", 8),
("fine_ts", 3),
("address", 16),
("data", 512),
]
dut = output_network.OutputNetwork(LANE_COUNT, LANE_COUNT*4, layout_payload)
output = []
def gen():
for n, input_event in enumerate(input_events):
yield dut.input[n].valid.eq(1)
yield dut.input[n].seqn.eq(n)
for k, v in input_event.items():
yield getattr(dut.input[n].payload, k).eq(v)
yield
for n in range(len(input_events)):
yield dut.input[n].valid.eq(0)
for i in range(output_network.latency(LANE_COUNT)):
yield
for x in range(LANE_COUNT):
if (yield dut.output[x].valid):
d = {
"replace_occured": (yield dut.output[x].replace_occured),
"channel": (yield dut.output[x].payload.channel),
"fine_ts": (yield dut.output[x].payload.fine_ts),
"address": (yield dut.output[x].payload.address),
"data": (yield dut.output[x].payload.data),
}
output.append(d)
run_simulation(dut, gen())
return output
class TestOutputNetwork(unittest.TestCase):
def test_replace(self):
for n_events in range(2, LANE_COUNT+1):
with self.subTest(n_events=n_events):
input = [{"channel": 1, "address": i} for i in range(n_events)]
output = simulate(input)
expect = [{'replace_occured': 1, 'channel': 1, 'fine_ts': 0, 'address': n_events-1, 'data': 0}]
self.assertEqual(output, expect)
def test_no_replace(self):
for n_events in range(1, LANE_COUNT+1):
with self.subTest(n_events=n_events):
input = [{"channel": i, "address": i} for i in range(n_events)]
output = simulate(input)
expect = [{'replace_occured': 0, 'channel': i, 'fine_ts': 0, 'address': i, 'data': 0}
for i in range(n_events)]
self.assertEqual(output, expect)

View File

@ -0,0 +1,88 @@
import unittest
import itertools
from migen import *
from artiq.gateware import rtio
from artiq.gateware.rtio import cri
from artiq.gateware.rtio.sed.core import *
from artiq.gateware.rtio.phy import ttl_simple
class DUT(Module):
def __init__(self):
self.ttl0 = Signal()
self.ttl1 = Signal()
self.submodules.phy0 = ttl_simple.Output(self.ttl0)
self.submodules.phy1 = ttl_simple.Output(self.ttl1)
rtio_channels = [
rtio.Channel.from_phy(self.phy0),
rtio.Channel.from_phy(self.phy1)
]
self.submodules.sed = SED(rtio_channels, 0, "sync")
self.sync += [
self.sed.coarse_timestamp.eq(self.sed.coarse_timestamp + 1),
self.sed.minimum_coarse_timestamp.eq(self.sed.coarse_timestamp + 16)
]
def simulate(input_events):
dut = DUT()
ttl_changes = []
access_results = []
def gen():
yield dut.sed.cri.chan_sel.eq(0)
for timestamp, data in input_events:
yield dut.sed.cri.timestamp.eq(timestamp)
yield dut.sed.cri.o_data.eq(data)
yield
yield dut.sed.cri.cmd.eq(cri.commands["write"])
yield
yield dut.sed.cri.cmd.eq(cri.commands["nop"])
access_time = 0
yield
while (yield dut.sed.cri.o_status) & 0x01:
yield
access_time += 1
status = (yield dut.sed.cri.o_status)
access_status = "ok"
if status & 0x02:
access_status = "underflow"
if (yield dut.sed.sequence_error):
access_status = "sequence_error"
access_results.append((access_status, access_time))
@passive
def monitor():
old_ttl_state = 0
for time in itertools.count():
ttl_state = yield dut.ttl0
if ttl_state != old_ttl_state:
ttl_changes.append(time)
old_ttl_state = ttl_state
yield
run_simulation(dut, {"sys": [
gen(), monitor(),
(None for _ in range(45))
]}, {"sys": 5, "rio": 5, "rio_phy": 5})
return ttl_changes, access_results
class TestSED(unittest.TestCase):
def test_sed(self):
input_events = [(18, 1), (20, 0), (25, 1), (30, 0)]
latency = 11
ttl_changes, access_results = simulate(input_events)
self.assertEqual(ttl_changes, [e[0] + latency for e in input_events])
self.assertEqual(access_results, [("ok", 0)]*len(input_events))

View File

@ -258,10 +258,10 @@ class SequenceError(EnvExperiment):
@kernel
def run(self):
self.core.reset()
t = now_mu()
self.ttl_out.pulse(25*us)
at_mu(t)
self.ttl_out.pulse(25*us)
delay(55*256*us)
for _ in range(256):
self.ttl_out.pulse(25*us)
delay(-75*us)
class Collision(EnvExperiment):
@ -276,6 +276,8 @@ class Collision(EnvExperiment):
for i in range(16):
self.ttl_out_serdes.pulse_mu(1)
delay_mu(1)
while self.core.get_rtio_counter_mu() < now_mu():
pass
class AddressCollision(EnvExperiment):
@ -288,6 +290,8 @@ class AddressCollision(EnvExperiment):
self.core.reset()
self.loop_in.input()
self.loop_in.pulse(10*us)
while self.core.get_rtio_counter_mu() < now_mu():
pass
class TimeKeepsRunning(EnvExperiment):
@ -358,7 +362,7 @@ class CoredeviceTest(ExperimentCase):
rtt = self.dataset_mgr.get("rtt")
print(rtt)
self.assertGreater(rtt, 0*ns)
self.assertLess(rtt, 60*ns)
self.assertLess(rtt, 140*ns)
def test_clock_generator_loopback(self):
self.execute(ClockGeneratorLoopback)
@ -397,27 +401,23 @@ class CoredeviceTest(ExperimentCase):
with self.assertRaises(RTIOUnderflow):
self.execute(Underflow)
def execute_and_test_in_log(self, experiment, string):
core_addr = self.device_mgr.get_desc("core")["arguments"]["host"]
mgmt = CommMgmt(core_addr)
mgmt.clear_log()
self.execute(experiment)
log = mgmt.get_log()
self.assertIn(string, log)
mgmt.close()
def test_sequence_error(self):
with self.assertRaises(RTIOSequenceError):
self.execute(SequenceError)
self.execute_and_test_in_log(SequenceError, "RTIO sequence error")
def test_collision(self):
core_addr = self.device_mgr.get_desc("core")["arguments"]["host"]
mgmt = CommMgmt(core_addr)
mgmt.clear_log()
self.execute(Collision)
log = mgmt.get_log()
self.assertIn("RTIO collision", log)
mgmt.close()
self.execute_and_test_in_log(Collision, "RTIO collision")
def test_address_collision(self):
core_addr = self.device_mgr.get_desc("core")["arguments"]["host"]
mgmt = CommMgmt(core_addr)
mgmt.clear_log()
self.execute(AddressCollision)
log = mgmt.get_log()
self.assertIn("RTIO collision", log)
mgmt.close()
self.execute_and_test_in_log(AddressCollision, "RTIO collision")
def test_watchdog(self):
# watchdog only works on the device
@ -491,7 +491,7 @@ class RPCTest(ExperimentCase):
class _DMA(EnvExperiment):
def build(self, trace_name="foobar"):
def build(self, trace_name="test_rtio"):
self.setattr_device("core")
self.setattr_device("core_dma")
self.setattr_device("ttl1")
@ -499,8 +499,12 @@ class _DMA(EnvExperiment):
self.delta = np.int64(0)
@kernel
def record(self):
def record(self, for_handle=True):
with self.core_dma.record(self.trace_name):
# When not using the handle, retrieving the DMA trace
# in dma.playback() can be slow. Allow some time.
if not for_handle:
delay(1*ms)
delay(100*ns)
self.ttl1.on()
delay(100*ns)
@ -519,20 +523,22 @@ class _DMA(EnvExperiment):
self.set_dataset("dma_record_time", self.core.mu_to_seconds(t2 - t1))
@kernel
def playback(self, use_handle=False):
self.core.break_realtime()
start = now_mu()
def playback(self, use_handle=True):
if use_handle:
handle = self.core_dma.get_handle(self.trace_name)
self.core.break_realtime()
start = now_mu()
self.core_dma.playback_handle(handle)
else:
self.core.break_realtime()
start = now_mu()
self.core_dma.playback(self.trace_name)
self.delta = now_mu() - start
@kernel
def playback_many(self, n):
self.core.break_realtime()
handle = self.core_dma.get_handle(self.trace_name)
self.core.break_realtime()
t1 = self.core.get_rtio_counter_mu()
for i in range(n):
self.core_dma.playback_handle(handle)
@ -579,9 +585,9 @@ class DMATest(ExperimentCase):
core_host = self.device_mgr.get_desc("core")["arguments"]["host"]
exp = self.create(_DMA)
exp.record()
for use_handle in [False, True]:
exp.record(use_handle)
get_analyzer_dump(core_host) # clear analyzer buffer
exp.playback(use_handle)
@ -603,9 +609,13 @@ class DMATest(ExperimentCase):
exp = self.create(_DMA)
exp.record()
for use_handle in [False, True]:
exp.playback(use_handle)
self.assertEqual(exp.delta, 200)
exp.record(False)
exp.playback(False)
self.assertEqual(exp.delta, 1000200)
exp.record(True)
exp.playback(True)
self.assertEqual(exp.delta, 200)
def test_dma_record_time(self):
exp = self.create(_DMA)
@ -618,11 +628,17 @@ class DMATest(ExperimentCase):
def test_dma_playback_time(self):
exp = self.create(_DMA)
count = 20000
exp.record()
exp.record_many(40)
exp.playback_many(count)
dt = self.dataset_mgr.get("dma_playback_time")
print("dt={}, dt/count={}".format(dt, dt/count))
self.assertLess(dt/count, 3*us)
self.assertLess(dt/count, 4.5*us)
def test_dma_underflow(self):
exp = self.create(_DMA)
exp.record()
with self.assertRaises(RTIOUnderflow):
exp.playback_many(20000)
def test_handle_invalidation(self):
exp = self.create(_DMA)

View File

@ -117,6 +117,22 @@ To track down ``RTIOUnderflows`` in an experiment there are a few approaches:
code.
* The :any:`integrated logic analyzer <core-device-rtio-analyzer-tool>` shows the timeline context that lead to the exception. The analyzer is always active and supports plotting of RTIO slack. RTIO slack is the difference between timeline cursor and wall clock time (``now - rtio_counter``).
Sequence errors
---------------
A sequence error happens when the sequence of coarse timestamps cannot be supported by the gateware. For example, there may have been too many timeline rewinds.
Internally, the gateware stores output events in an array of FIFO buffers (the "lanes") and the timestamps in each lane much be strictly increasing. The gateware selects a different lane when an event with a decreasing or equal timestamp is submitted. A sequence error occurs when no appropriate lane can be found.
Notes:
* Strictly increasing timestamps never cause sequence errors.
* Configuring the gateware with more lanes for the RTIO core reduces the frequency of sequence errors.
* Whether a particular sequence of timestamps causes a sequence error or not is fully deterministic (starting from a known RTIO state, e.g. after a reset). Adding a constant offset to the whole sequence does not affect the result.
The offending event is discarded and the RTIO core keeps operating.
This error is reported asynchronously via the core device log: for performance reasons with DRTIO, the CPU does not wait for an error report from the satellite after writing an event. Therefore, it is not possible to raise an exception precisely.
Collisions
----------
A collision happens when more than one event is submitted on a given channel with the same coarse timestamp, and that channel does not implement replacement behavior or the fine timestamps are different.