Fix bug where top 2 bits were getting lost in the modulo

ChaCha20_Poly1305_64/sim/poly1305_friendly_modular_mult.py

@@ -78,7 +78,7 @@ async def test_sanity(dut):
 
     await tb.cycle_reset()
 
-    count = 16
+    count = 1024
 
     for _ in range(count):
         await tb.write_input(random.randint(1,2**128-1), random.randint(0, 2**130-6))
@@ -93,6 +93,4 @@ async def test_sanity(dut):
             tb.log.info(f"{sim_val:x} -> {dut_val:x}")
             fail = True
 
-    # assert not fail
-
-    await Timer(1, "us")
+    assert not fail

ChaCha20_Poly1305_64/sim/poly1305_friendly_modulo.py

@@ -88,4 +88,23 @@ async def test_sanity(dut):
             tb.log.info(f"{sim_val:x} -> {dut_val:x}")
             fail = True
 
+    assert not fail
+
+@cocotb.test
+async def test_directed(dut):
+    tb = TB(dut)
+
+    await tb.cycle_reset()
+
+    await tb.write_input(0x14C0D69391E7116E057E7AD833B00B706AA2390C, 4)
+
+    fail = False
+
+    sim_val = await tb.expected_queue.get()
+    dut_val = await tb.output_queue.get()
+
+    if sim_val != dut_val:
+        tb.log.info(f"{sim_val:x} -> {dut_val:x}")
+        fail = True
+
     assert not fail