bs/BusTypes.bs

@@ -57,9 +57,9 @@ interface BusMaster =
   -- This has implications about for the implementor of BusMaster, namely, that it
   -- should hold its request until it's request method gets called.
   request  :: BusRequest
-  -- From the masters's perspective, the response should not be called until
+  -- From the masters's perspective, the response should not be called by the
-  -- the client is ready to accept the response. In other words, response
+  -- arbiter until the master is ready to accept the response. In other words,
-  -- should be guarded by the client.
+  -- response should be guarded by the client.
   response :: BusResponse -> Action
 
 type Token = UInt 5

bs/TagEngine.bs

@@ -9,7 +9,7 @@ import Util
 #define UIntLog2N(n) (UInt (TLog n))
 
 interface (TagEngine :: # -> *) numTags =
-    requestTag :: ActionValue UIntLog2N(numTags)
+    requestTag :: ActionValue (Maybe UIntLog2N(numTags))
     retireTag  :: UIntLog2N(numTags) -> ActionValue BasicResult
 
 -- The tag engine returns a tag that is unique for the duration of
@@ -19,6 +19,7 @@ interface (TagEngine :: # -> *) numTags =
 mkTagEngine :: Module (TagEngine numTags)
 mkTagEngine =
     do
+
         let reifiedNumTags = fromInteger |> valueOf numTags
 
         freeStackVec :: Vector numTags (Reg UIntLog2N(numTags))
@@ -30,8 +31,20 @@ mkTagEngine =
         stackPtr :: (Reg (Maybe(UIntLog2N(numTags))))
         stackPtr <- mkReg |> Just |> reifiedNumTags - 1
 
+        methodRequestTagCalled :: PulseWire
+        methodRequestTagCalled <- mkPulseWire
+
+
+        methodRetireTagCalled :: PulseWire
+        methodRetireTagCalled <- mkPulseWire
+
+        tagResponse :: RWire UIntLog2N(numTags)
+        tagResponse <- mkRWireSBR
+
         debugOnce <- mkReg True
 
+        tt :: Reg Bool <- mkReg False
+
         addRules $
             rules
                 "display": when (debugOnce == True) ==>
@@ -40,20 +53,30 @@ mkTagEngine =
                         $display "inUseVec : " (fshow |> readVReg inUseVec)
                         $display "stackPtr : " (fshow stackPtr)
                         debugOnce := False
+            <+>
+            rules
+                when (methodRequestTagCalled && methodRetireTagCalled) ==>
+                    do
+                        $display "ho ho ho"
+                        -- let 
+                        --     nextStackPtr = 
+                        --         case of (methodRequestTagCalled, methodRetireTagCalled) of
+                        --             (True, True) -> 
 
         counter <- mkReg(0 :: UIntLog2N(numTags))
         return $
           interface TagEngine
 
-            requestTag :: ActionValue UIntLog2N(numTags)
+            requestTag :: ActionValue (Maybe UIntLog2N(numTags))
             requestTag =
                 do
+                    methodRequestTagCalled.send
                     stackPtr :=
                         if sampledStackPtr == 0
                             then Nothing
                             else Just |> sampledStackPtr - 1
                     (select inUseVec sampledStackPtr) := True
-                    return |> readReg (select freeStackVec sampledStackPtr)
+                    return |> Just |> readReg (select freeStackVec sampledStackPtr)
                 when
                     Just sampledStackPtr <- stackPtr
 
@@ -64,6 +87,7 @@ mkTagEngine =
             retireTag :: UIntLog2N(numTags) -> ActionValue BasicResult
             retireTag tag =
                 do
+                    methodRetireTagCalled.send
                     let
                         tagValid = tag < reifiedNumTags
                         tagInUse = readReg (select inUseVec tag)

bs/Top.bs

@@ -108,21 +108,24 @@ mkSim = do
   core             :: Core FCLK <- mkCore;
 
   s :: ActionSeq
-  s <- actionSeq
+  s <- 
-    $  do
+    let
-         $display "got tag : " tagEngine.requestTag
+      requestTagAction :: Action
-    |> do
+      requestTagAction =
-         $display "got tag : " tagEngine.requestTag
+        do
-    |> do
+          tag <- tagEngine.requestTag
-         $display "got tag : " tagEngine.requestTag
+          $display "got tag : " (fshow tag)
+    in
+      actionSeq $
+      do requestTagAction
+      |> do requestTagAction
+      |> do requestTagAction
       |> do
           res <- tagEngine.retireTag 3
           $display "retiring tag :   3 " (fshow res)
           action {}
-    |> do
+      |> do requestTagAction
-         $display "got tag : " tagEngine.requestTag
+      |> do requestTagAction
-    |> do
-         $display "got tag : " tagEngine.requestTag
       |> do
           res <- tagEngine.retireTag 4
           $display "retiring tag :   4 " (fshow res)
@@ -135,16 +138,13 @@ mkSim = do
           res <- tagEngine.retireTag 0
           $display "retiring tag :   0 " (fshow res)
           action {}
-    |> do
+      |> do requestTagAction
-         $display "got tag : " tagEngine.requestTag
+      |> do requestTagAction
-    |> do
-         $display "got tag : " tagEngine.requestTag
       |> do
           res <- tagEngine.retireTag 1
           $display "retiring tag :   1 " (fshow res)
           action {}
-    |> do
+      |> do requestTagAction
-         $display "got tag : " tagEngine.requestTag
 
   addRules $
     rules