From 98b75d8671cba8eaaa41ff739dae4eccf44f367a Mon Sep 17 00:00:00 2001
From: Blake Smith <blakesmith0@gmail.com>
Date: Thu, 21 Jan 2021 21:37:41 -0600
Subject: [PATCH] Add initial core test for Timer

---
 test/test_timer.py | 63 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 test/test_timer.py

diff --git a/test/test_timer.py b/test/test_timer.py
new file mode 100644
index 000000000..2050267f0
--- /dev/null
+++ b/test/test_timer.py
@@ -0,0 +1,63 @@
+import unittest
+
+from migen import *
+
+from litex.soc.cores.timer import Timer
+
+class TestTimer(unittest.TestCase):
+    def test_one_shot_software_polling(self):
+        def generator(timer):
+            clock_cycles = 25
+            yield from timer._en.write(0)
+            yield from timer._load.write(clock_cycles)
+            yield from timer._reload.write(0)
+            yield from timer._en.write(1)
+            yield from timer._update_value.write(1)
+            yield
+            self.assertTrue((yield timer._value.status) > 0)
+            while (yield timer._value.status) > 0:
+                yield from timer._update_value.write(1)
+            yield
+            self.assertEqual((yield timer._value.status), 0)
+
+        timer = Timer()
+        run_simulation(timer, generator(timer))
+
+    def test_periodic_timer_software_polling(self):
+        def generator(timer):
+            clock_cycles = 25
+            yield from timer._en.write(0)
+            yield from timer._load.write(0)
+            yield from timer._reload.write(clock_cycles)
+            yield from timer._en.write(1)
+            yield from timer._update_value.write(1)
+            yield
+            self.assertTrue((yield timer._value.status) > 0)
+            while (yield timer._value.status) > 0:
+                yield from timer._update_value.write(1)
+            yield
+            # Ensure that the timer reloads
+            self.assertEqual((yield timer._value.status), clock_cycles)
+
+        timer = Timer()
+        run_simulation(timer, generator(timer))
+
+    def test_one_shot_timer_interrupts(self):
+        def generator(timer):
+            clock_cycles = 25
+            yield from timer._en.write(0)
+            yield from timer._load.write(clock_cycles)
+            yield from timer._reload.write(0)
+            yield from timer.ev.enable.write(1)
+
+            self.assertEqual(1, (yield timer.ev.zero.trigger))
+
+            yield from timer._en.write(1)
+
+            while (yield timer.ev.zero.trigger != 0) and clock_cycles >= -5:
+                yield
+                clock_cycles -= 1
+            self.assertEqual(0, (yield timer.ev.zero.trigger))
+
+        timer = Timer()
+        run_simulation(timer, generator(timer))