From 7b7afcc3109368edd8a1bc7d492ba4a1cf0a1d0c Mon Sep 17 00:00:00 2001
From: Daniel Benusovich <flyingmonkeys1996@gmail.com>
Date: Mon, 18 Feb 2019 21:02:37 -0800
Subject: [PATCH] Big update. Now with some unit testing weeeoow!

---
 TLB/CamEntry.py | 100 ++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 83 insertions(+), 17 deletions(-)

diff --git a/TLB/CamEntry.py b/TLB/CamEntry.py
index 6351d0eb..f8f36449 100644
--- a/TLB/CamEntry.py
+++ b/TLB/CamEntry.py
@@ -1,10 +1,11 @@
 from nmigen import Module, Signal
-from nmigen.cli import main
+from nmigen.compat.fhdl.structure import If
+from nmigen.compat.sim import run_simulation
 
-class CamEntry():
+class CamEntry:
     def __init__(self, key_size, data_size):
         # Internal
-        key = Signal(key_size)
+        self.key = Signal(key_size)
         
         # Input
         self.write = Signal(1) # Read => 0 Write => 1
@@ -16,18 +17,83 @@ class CamEntry():
         self.data = Signal(data_size)
         
         
-    def elabotate(self, platform):
+    def get_fragment(self, platform=None):
         m = Module()
-        m.d.comb += [
-            If(self.write == 1,
-               key.eq(self.key_in),
-               self.data.eq(self.data_in)
-            ).Else(
-                If(self.key_in == key,
-                   self.match.eq(0)
-                ).Else(
-                    self.match.eq(1)
-                )
-            )
-        ]
-        return m
\ No newline at end of file
+        with m.If(self.write == 1):
+            m.d.comb += [
+                self.key.eq(self.key_in),
+                self.data.eq(self.data_in),
+                self.match.eq(1)
+            ]
+        with m.Else():
+            with m.If(self.key_in == self.key):
+                m.d.comb += self.match.eq(0)
+            with m.Else():
+                m.d.comb += self.match.eq(1)
+        
+        return m
+    
+#########    
+# TESTING
+########
+ 
+# This function allows for the easy setting of values to the Cam Entry
+# unless the key is incorrect
+# Arguments:
+#   dut: The CamEntry being tested
+#   w (write): Read (0) or Write (1)
+#   k (key): The key to be set
+#   d (data): The data to be set  
+def set_cam(dut, w, k, d):
+    yield dut.write.eq(w)
+    yield dut.key_in.eq(k)
+    yield dut.data_in.eq(d)
+    yield
+    
+def check(pre, e, out, op):
+    if(op == 0):
+        assert out == e, pre + " Output " + str(out) + " Expected " + str(e)
+    else:
+        assert out != e, pre + " Output " + str(out) + " Expected " + str(e) 
+    
+def check_key(dut, k, op):
+    out_k = yield dut.key
+    check("K", out_k, k, op)   
+    
+def check_data(dut, d, op):
+    out_d = yield dut.data
+    check("D", out_d, d, op)   
+    
+def check_match(dut, m, op):
+    out_m = yield dut.match
+    check("M", out_m, m, op)  
+    
+def check_all(dut, k, d, m, kop, dop, mop):
+    yield from check_key(dut, k, kop)
+    yield from check_data(dut, d, dop)
+    yield from check_match(dut, m, mop)
+    
+# This testbench goes through the paces of testing the CamEntry module
+# It is done by writing and then reading various combinations of key/data pairs
+# and reading the results with varying keys to verify the resulting stored
+# data is correct.
+def testbench(dut):
+    # Check write
+    write = 1
+    key = 0
+    data = 1
+    match = 1
+    yield from set_cam(dut, write, key, data)
+    yield from check_all(dut, key, data, match, 0, 0, 0)
+    
+    # Check read miss
+    write = 0
+    key = 2
+    data = 1
+    match = 0 
+    yield from set_cam(dut, write, key, data)
+    yield from check_all(dut, key, data, match, 1, 0, 0)    
+    
+if __name__ == "__main__":
+    dut = CamEntry(4, 4)
+    run_simulation(dut, testbench(dut), vcd_name="Waveforms/cam_entry_test.vcd")
\ No newline at end of file
-- 
2.30.2