From 8e758ecc17a36d3d2114de01627090ff17e211c1 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Wed, 15 Jul 2020 23:06:34 +0800
Subject: [PATCH] add RTIO analyzer core (untested)

---
 src/gateware/analyzer.py | 111 +++++++++++++++++++++++++++++++++++++++
 src/gateware/zc706.py    |   6 ++-
 2 files changed, 116 insertions(+), 1 deletion(-)
 create mode 100644 src/gateware/analyzer.py

diff --git a/src/gateware/analyzer.py b/src/gateware/analyzer.py
new file mode 100644
index 0000000..7a8f4d1
--- /dev/null
+++ b/src/gateware/analyzer.py
@@ -0,0 +1,111 @@
+from migen import *
+
+from misoc.interconnect.csr import *
+from misoc.interconnect import stream
+from migen_axi.interconnect import axi
+
+from artiq.gateware.rtio.analyzer import message_len, MessageEncoder
+
+
+class AXIDMAWriter(Module, AutoCSR):
+    def __init__(self, membus, max_outstanding_requests):
+        aw = len(membus.aw.addr)
+        dw = len(membus.w.data)
+        assert message_len % dw == 0
+        burst_length = message_len//dw
+        alignment_bits = log2_int(message_len//8)
+
+        self.reset = CSR()  # only apply when shut down
+        # All numbers in bytes
+        self.base_address = CSRStorage(aw, alignment_bits=alignment_bits)
+        self.last_address = CSRStorage(aw, alignment_bits=alignment_bits)
+        self.byte_count = CSRStatus(64)  # only read when shut down
+
+        self.make_request = Signal()
+        self.sink = stream.Endpoint([("data", dw)])
+
+        # # #
+
+        outstanding_requests = Signal(max=max_outstanding_requests+1)
+        current_address = Signal(aw - alignment_bits)
+        self.comb += [
+            membus.aw.addr.eq(Cat(C(0, alignment_bits), current_address)),
+            membus.aw.id.eq(0),                   # Same ID for all transactions to forbid reordering.
+            membus.aw.burst.eq(axi.Burst.incr.value),
+            membus.aw.len.eq(burst_length-1),     # Number of transfers in burst (0->1 transfer, 1->2 transfers...).
+            membus.aw.size.eq(log2_int(dw//8)),   # Width of burst: 3 = 8 bytes = 64 bits.
+            membus.aw.cache.eq(0xf),
+            membus.aw.valid.eq(outstanding_requests != 0),
+        ]
+        self.sync += [
+            outstanding_requests.eq(outstanding_requests + self.make_request - (membus.aw.valid & membus.aw.ready)),
+
+            If(self.reset.re,
+                current_address.eq(self.base_address.storage)),
+            If(membus.aw.valid & membus.aw.ready,
+                If(current_address == self.last_address.storage,
+                    current_address.eq(self.base_address.storage)
+                ).Else(
+                    current_address.eq(current_address + 1)
+                )
+            )
+        ]
+
+        self.comb += [
+            membus.w.valid.eq(self.sink.stb),
+            self.sink.ack.eq(membus.w.ready),
+            membus.w.data.eq(self.sink.data)
+        ]
+        beat_count = Signal(max=burst_length)
+        self.sync += [
+            If(membus.w.valid & membus.w.ready,
+                membus.w.last.eq(0),
+                If(membus.w.last,
+                    beat_count.eq(0)
+                ).Else(
+                    If(beat_count == burst_length-2, membus.w.last.eq(1)),
+                    beat_count.eq(beat_count + 1)
+                )
+            )
+        ]
+
+        message_count = Signal(64 - log2_int(message_len//8))
+        self.comb += self.byte_count.status.eq(
+            message_count << log2_int(message_len//8))
+        self.sync += [
+            If(self.reset.re, message_count.eq(0)),
+            If(membus.w.valid & membus.w.ready & membus.w.last, message_count.eq(message_count + 1))
+        ]
+
+        self.comb += membus.b.ready.eq(1)
+
+
+class Analyzer(Module, AutoCSR):
+    def __init__(self, tsc, cri, membus, fifo_depth=128):
+        # shutdown procedure: set enable to 0, wait until busy=0
+        self.enable = CSRStorage()
+        self.busy = CSRStatus()
+
+        self.submodules.message_encoder = MessageEncoder(
+            tsc, cri, self.enable.storage)
+        self.submodules.fifo = stream.SyncFIFO(
+            [("data", message_len)], fifo_depth, True)
+        self.submodules.converter = stream.Converter(
+            message_len, len(membus.w.data), reverse=True)
+        self.submodules.dma = AXIDMAWriter(membus, max_outstanding_requests=fifo_depth)
+
+        enable_r = Signal()
+        self.sync += [
+            enable_r.eq(self.enable.storage),
+            If(self.enable.storage & ~enable_r,
+                self.busy.status.eq(1)),
+            If(self.dma.sink.stb & self.dma.sink.ack & self.dma.sink.eop,
+                self.busy.status.eq(0))
+        ]
+
+        self.comb += [
+            self.message_encoder.source.connect(self.fifo.sink),
+            self.fifo.source.connect(self.converter.sink),
+            self.converter.source.connect(self.dma.sink),
+            self.dma.make_request.eq(self.fifo.sink.stb & self.fifo.sink.ack)
+        ]
diff --git a/src/gateware/zc706.py b/src/gateware/zc706.py
index cb94a1e..18c4ea4 100755
--- a/src/gateware/zc706.py
+++ b/src/gateware/zc706.py
@@ -13,8 +13,8 @@ from misoc.integration import cpu_interface
 from artiq.gateware import rtio, nist_clock, nist_qc2
 from artiq.gateware.rtio.phy import ttl_simple, ttl_serdes_7series, dds, spi2
 
-
 import dma
+import analyzer
 
 
 class RTIOCRG(Module, AutoCSR):
@@ -96,6 +96,10 @@ class ZC706(SoCCore):
         self.submodules.rtio_moninj = rtio.MonInj(rtio_channels)
         self.csr_devices.append("rtio_moninj")
 
+        self.submodules.rtio_analyzer = analyzer.Analyzer(self.rtio_tsc, self.rtio_core.cri,
+                                                          self.ps7.s_axi_hp1)
+        self.csr_devices.append("rtio_analyzer")
+
 
 class Simple(ZC706):
     def __init__(self):