From d37577a8a115fcda593f185d8f03222bd39ae6fd Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Tue, 19 Sep 2017 15:30:30 +0800
Subject: [PATCH] rtio: add input collector module

---
 artiq/gateware/rtio/input_collector.py | 139 +++++++++++++++++++++++++
 1 file changed, 139 insertions(+)
 create mode 100644 artiq/gateware/rtio/input_collector.py

diff --git a/artiq/gateware/rtio/input_collector.py b/artiq/gateware/rtio/input_collector.py
new file mode 100644
index 000000000..b0962adb5
--- /dev/null
+++ b/artiq/gateware/rtio/input_collector.py
@@ -0,0 +1,139 @@
+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
+
+
+__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)
+            )
+        ]