Add _DelayLine test

diff --git a/gram/test/test_core_crossbar.py b/gram/test/test_core_crossbar.py
new file mode 100644 (file)
index 0000000..a2da8aa
--- /dev/null
+++ b/gram/test/test_core_crossbar.py
@@ -0,0 +1,28 @@
+from nmigen import *
+from nmigen.hdl.ast import Sample
+from nmigen.asserts import Assert, Assume
+
+from gram.core.crossbar import _DelayLine
+from utils import *
+
+class DelayLineSpec(Elaboratable):
+    def __init__(self, delay):
+        self.delay = delay
+
+    def elaborate(self, platform):
+        m = Module()
+
+        m.submodules.dut = dut = _DelayLine(self.delay)
+        m.d.comb += Assume(~ResetSignal("sync"))
+        m.d.comb += Assert(dut.o == Sample(expr=dut.i, clocks=self.delay, domain="sync"))
+
+        return m
+
+class DelayLineTestCase(FHDLTestCase):
+    def test_delay_one(self):
+        spec = DelayLineSpec(1)
+        self.assertFormal(spec, depth=2)
+
+    def test_delay_many(self):
+        spec = DelayLineSpec(10)
+        self.assertFormal(spec, depth=11)