MulPlugin.bufferedHigh added

SpinalHDL · Oct 13, 2023 · 8124eb4 · 8124eb4
1 parent 9e44c1b
commit 8124eb4
Showing 1 changed file with 13 additions and 2 deletions.
diff --git a/src/main/scala/naxriscv/execute/MulPlugin.scala b/src/main/scala/naxriscv/execute/MulPlugin.scala
@@ -33,7 +33,8 @@ class MulPlugin(val euId : String,
                 var splitWidthB : Int = 17,
                 var sum1WidthMax : Int = -1,
                 var sum2WidthMax : Int = -1,
-                var staticLatency : Boolean = true) extends ExecutionUnitElementSimple(euId, staticLatency) {
+                var staticLatency : Boolean = true,
+                var bufferedHigh : Boolean = false) extends ExecutionUnitElementSimple(euId, staticLatency) {
   import MulPlugin._
 
   override def euWritebackAt = writebackAt
@@ -46,6 +47,11 @@ class MulPlugin(val euId : String,
 
     getServiceOption[PrivilegedService].foreach(_.addMisa('M'))
 
+    if(bufferedHigh) {
+      eu.setDecodingDefault(HIGH, False)
+      assert(!staticLatency)
+    }
+
     add(Rvi.MUL   , List(), DecodeList(HIGH -> False, RS1_SIGNED -> True,  RS2_SIGNED -> True))
     add(Rvi.MULH  , List(), DecodeList(HIGH -> True,  RS1_SIGNED -> True,  RS2_SIGNED -> True))
     add(Rvi.MULHSU, List(), DecodeList(HIGH -> True,  RS1_SIGNED -> True,  RS2_SIGNED -> False))
@@ -120,7 +126,12 @@ class MulPlugin(val euId : String,
 
     val writeback = new ExecuteArea(writebackAt) {
       import stage._
-      wb.payload := B(HIGH ? stage(MUL_SUM3)(XLEN, XLEN bits) otherwise stage(MUL_SUM3)(0, XLEN bits))
+      val buffer = bufferedHigh generate new Area{
+        val valid = RegNext(False) init (False) setWhen (isValid && !isReady && !isRemoved)
+        val data = RegNext(stage(MUL_SUM3)(XLEN, XLEN bits))
+        haltIt(HIGH && !valid)
+      }
+      wb.payload := B(HIGH ? (if(bufferedHigh) buffer.data else stage(MUL_SUM3)(XLEN, XLEN bits)) otherwise stage(MUL_SUM3)(0, XLEN bits))
     }
   }