尝试速率配平，回环改到phy上

src/main/scala/backBoard/shin/ShinTop.scala

@@ -72,9 +72,15 @@ abstract class ShinTopBase extends Module{
   upCDRIn.io.overCLK := io.clk8x
 
   io.dDatOut := downCDROut.io.serDat
-
   io.uDatOut := upCDROut.io.serDat
 
+  //override
+  when( slaveParser.io.isLoop & io.modeSel === false.B){
+    upCDRIn.io.serDat := downCDROut.io.serDat
+    io.dDatOut := false.B
+  }
+
+
   val smUnit = Seq(
     Module( new SMUnit(depth = 4) ),
     Module( new SMUnit(depth = 4) ),