From a2b78941345ed8993ec5891b7a962ad2a1c75915 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Mon, 11 Sep 2017 23:05:10 +0800
Subject: [PATCH] rtio/sed: add output driver simulation unittest

---
 .../test/rtio/test_sed_output_driver.py       | 125 ++++++++++++++++++
 1 file changed, 125 insertions(+)
 create mode 100644 artiq/gateware/test/rtio/test_sed_output_driver.py

diff --git a/artiq/gateware/test/rtio/test_sed_output_driver.py b/artiq/gateware/test/rtio/test_sed_output_driver.py
new file mode 100644
index 000000000..ef61b98ea
--- /dev/null
+++ b/artiq/gateware/test/rtio/test_sed_output_driver.py
@@ -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, 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.phy3, ofifo_depth=4),
+        ]
+
+        self.submodules.output_driver = output_driver.OutputDriver(
+            rtio_channels, 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}, vcd_name="foo.vcd")
+    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")