使用未使用4b/5b编码作为preamble

src/main/scala/backBoard/ebus/CDROut.scala

@@ -24,8 +24,8 @@ class CDROut extends Module{
   def STATE_PREAMBLE = 1.U
   def STATE_PAYLOAD = 2.U
 
-  val ETH_PRE = "h55".U(8.W)
-  val ETH_SFD = "hD5".U(8.W)
+  val ETH_PRE = "b1100010001".U(10.W)
+  val ETH_SFD = "b0110100111".U(10.W)
 
   val stateNext = Wire(UInt(2.W))
   val stateCurr = RegNext( stateNext, 0.U )
@@ -52,14 +52,14 @@ class CDROut extends Module{
 
 
   when( stateCurr === STATE_IDLE & stateNext === STATE_PREAMBLE){ //PRE
-    shiftData := Dualb4b5Encoder(ETH_PRE)
+    shiftData := ETH_PRE
   } .otherwise{
     when( bitCnt =/= 9.U ){
       shiftData := shiftData << 1
     } .otherwise{ //bitCnt === 9.U
       when( stateCurr === STATE_PREAMBLE ){
-        shiftData := MuxCase( Dualb4b5Encoder(ETH_PRE), Array(
-          ( byteCnt === 6.U ) -> Dualb4b5Encoder(ETH_SFD),
+        shiftData := MuxCase( ETH_PRE, Array(
+          ( byteCnt === 6.U ) -> ETH_SFD,
           ( byteCnt === 7.U ) -> Dualb4b5Encoder(io.axis.bits.tdata),
         ))
       } .elsewhen( stateCurr === STATE_PAYLOAD ){